Another useful part of being an informed learner is recognizing that as a college student you will have many choices when it comes to learning. Looking back at the Uses and Gratification model, you’ll discover that your motivations as well as your choices in how you interact with learning activities can make a significant difference in not only what you learn, but how you learn. By being aware of a few learning theories, students can take initiative and tailor their own learning so that it best benefits them and meets their main needs.
Making Decisions about Your Own Learning
As a learner, the kinds of materials, study activities, and assignments that work best for you will derive from your own experiences and needs (needs that are both short-term as well as those that fulfill long-term goals). In order to make your learning better suited to meet these needs, you can use the knowledge you have gained about UGT and other learning theories to make decisions concerning your own learning. These decisions can include personal choices in learning materials, how and when you study, and most importantly, taking ownership of your learning activities as an active participant and decision maker. In fact, one of the main principles emphasized in this chapter is that students not only benefit from being involved in planning their instruction, but learners also gain by continually evaluating the actual success of that instruction. In other words:
Does this work for me? Am I learning what I need to by doing it this way?
While it may not always be possible to control every component of your learning over an entire degree program, you can take every opportunity to influence learning activities so they work to your best advantage. What follows are several examples of how this can be done by making decisions about your learning activities based on what you have already learned in this chapter.
Make Mistakes Safe
Create an environment for yourself where mistakes are safe and mistakes are expected as just another part of learning. This practice ties back to the principles you learned in the section on grit and persistence. The key is to allow yourself the opportunity to make mistakes and learn from them
before
they become a part of your grades. You can do this by creating your own learning activities that you design to do just that. An example of this might be taking practice quizzes on your own, outside of the more formal course activities. The quizzes could be something you find in your textbook, something you find online, or something that you develop with a partner. In the latter case you would arrange with a classmate for each of you to produce a quiz and then exchange them. That particular exercise would serve double learning duty, since to create a good quiz you would need to learn the main concepts of the subject, and answering the questions on your partner’s quiz might help you identify areas where you need more knowledge.
The main idea with this sort of practice is that you are creating a safe environment where you can make mistakes and learn from them before those mistakes can negatively impact your success in the course. Better to make mistakes on a practice run than on any kind of assignment or exam that can heavily influence your final grade in a course.
Make Everything Problem Centered
When working through a learning activity, the practical act of problem-solving is a good strategy. Problem-solving, as an approach, can give a learning activity more meaning and motivation for you, as a learner. Whenever possible it is to your advantage to turn an assignment or learning task into a problem you are trying to solve or something you are trying to accomplish.
In essence, you do this by deciding on some purpose for the assignment (other than just completing the assignment itself). An example of this would be taking the classic college term paper and writing it in a way that solves a problem you are already interested in.
Typically, many students treat a term paper as a collection of requirements that must be fulfilled—the paper must be on a certain topic; it should include an introduction section, a body, a closing, and a bibliography; it should be so many pages long, etc. With this approach, the student is simply completing a checklist of attributes and components dictated by the instructor, but other than that, there is no reason for the paper to exist.
Instead, writing it to solve a problem gives the paper purpose and meaning. For example, if you were to write a paper with the purpose of informing the reader about a topic they knew little about, that purpose would influence not only how you wrote the paper but would also help you make decisions on what information to include. It would also influence how you would structure information in the paper so that the reader might best learn what you were teaching them. Another example would be to write a paper to persuade the reader about a certain opinion or way of looking at things. In other words, your paper now has a purpose rather than just reporting facts on the subject. Obviously, you would still meet the format requirements of the paper, such as number of pages and inclusion of a bibliography, but now you do that in a way that helps to solve your problem.
Make It Occupation Related
Much like making assignments problem centered, you will also do well when your learning activities have meaning for your profession or major area of study. This can take the form of simply understanding how the things you are learning are important to your occupation, or it can include the decision to do assignments in a way that can be directly applied to your career. If an exercise seems pointless and possibly unrelated to your long-term goals, you will be much less motivated by the learning activity.
An example of understanding how a specific school topic impacts your occupation future would be that of a nursing student in an algebra course. At first, algebra might seem unrelated to the field of nursing, but if the nursing student recognizes that drug dosage calculations are critical to patient safety and that algebra can help them in that area, there is a much stronger motivation to learn the subject.
In the case of making a decision to apply assignments directly to your field, you can look for ways to use learning activities to build upon other areas or emulate tasks that would be required in your profession. Examples of this might be a communication student giving a presentation in a speech course on how the Internet has changed corporate advertising strategies, or an accounting student doing statistics research for an environmental studies course. Whenever possible, it is even better to use assignments to produce things that are much like what you will be doing in your chosen career. An example of this would be a graphic design student taking the opportunity to create an infographic or other supporting visual elements as a part of an assignment for another course. In cases where this is possible, it is always best to discuss your ideas with your instructor to make certain what you intend will still meet the requirements of the assignment.
Managing Your Time
One of the most common traits of college students is the constraint on their time. As adults, we do not always have the luxury of attending school without other demands on our time. Because of this, we must become efficient with our use of time, and it is important that we maximize our learning activities to be most effective. In fact, time management is so important that there is an entire chapter in this text dedicated to it. When you can, refer to that chapter to learn more about time management concepts and techniques that can be very useful.
Instructors as Learning Partners
In K-12 education, the instructor often has the dual role of both teacher and authority figure for students. Children come to expect their teachers to tell them what to do, how to do it, and when to do it. College learners, on the other hand, seem to work better when they begin to think of their instructors as respected experts that are partners in their education. The change in the relationship for you as a learner accomplishes several things: it gives you ownership and decision-making ability in your own learning, and it enables you to personalize your learning experience to best fit your own needs. For the instructor, it gives them the opportunity to help you meet your own needs and expectations in a rich experience, rather than focusing all of their time on trying to get information to you.
The way to develop learning partnerships is through direct communication with your instructors. If there is something you do not understand or need to know more about, go directly to them. When you have ideas about how you can personalize assignments or explore areas of the subject that interest you or better fit your needs, ask them about it. Ask your instructors for guidance and recommendations, and above all, demonstrate to them that you are taking a direct interest in your own learning. Most instructors are thrilled when they encounter students that want to take ownership of their own learning, and they will gladly become a resourceful guide for you.
Application
Applying What You Know about Learning to What You Are Doing:
In this activity, you will work with an upcoming assignment from one of your courses—preferably something you might be dreading or are at least less than enthusiastic about working on. You will see if there is anything you can apply to the assignment from what you know about learning that might make it more interesting.
In the table below are several attributes that college students generally prefer in their learning activities, listed in the far left column. As you think about your assignment, consider whether or not it already possesses the attribute. If it does, go on to the next row. If it does not, see if there is some way you can approach the assignment so that it does follow preferred learning attributes; write that down in the last column, to the far right.
Table 3.5
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Does it …?
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Yes
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No
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What you can do to turn the assignment into something that is better suited to you as a learner?
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Does it allow you to make decisions about your own learning?
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In essence, you are doing this right now. You are making decisions on how you can make your assignment more effective for you.
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Does it allow you to make mistakes without adversely affecting your grade?
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|
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Hints:
Are there ways for you to practice? Can you create a series of drafts for the assignment and get feedback?
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Is it centered on solving a problem?
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Hint:
Can you turn the assignment into something that solves a problem? An example would be making a presentation that actually educated others rather than just covered what you may have learned.
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Is it related to your chosen occupation in any way?
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Hint:
Can you turn the assignment into something you might actually do as a part of your profession or make it about your profession? Examples might be creating an informative poster for the workplace or writing a paper on new trends in your profession.
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Does it allow you to manage the time you work on it?
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More than likely the answer here will be “yes,” but you can plan how you will do it. For more information on this, see the chapter on time management.
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Does it allow interaction with your instructor as a learning partner?
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Hint:
Talking to your instructor about the ideas you have for making this assignment more personalized accomplishes this exact thing.
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2.5: Families at Higher Risk for Poor Health Outcomes
By the end of this section, you will be able to:
- Identify families in the community at higher risk for poor health outcomes and their experiences with the health-care system
- List health risk factors affecting families who are at increased risk during pregnancy and birth
- Identify and discuss social determinants of health in the childbearing population
Families can be at higher risk due to discrimination, poverty, injustice, or psychosocial issues. The nurse encounters these families in health-care settings as well as in the community. The nurse should use culturally sensitive approaches with these families and join community or professional groups to address health disparities in the community. The United States used nonmedical factors that influence health outcomes to develop Healthy People 2030 objectives in an attempt to address these disparities.
Characteristics of Families at Higher Risk for Poor Health Outcomes
Racial, sexual, or gender minorities; children; older adults; and people who are underinsured, socioeconomically disadvantaged, incarcerated, or disabled are at higher risk for poor health outcomes. Many low-income jobs do not provide health insurance, which reduces access to health care. These families can be stigmatized and may refrain from seeking health care due to fear of being marginalized. The nurse must be aware of different types of families at higher risk and how to provide them with fair and safe care.
Black Families
Black Americans in the United States have experienced a long history of racism, and inequity has become part of the infrastructure causing structural racism (Lloyd et al., 2021). Culturally, many Black Americans value marriage and children; however, barriers such as low income have often prevented these family structures from occurring. A study by Lloyd et al. (2021) found that having a low income led to increased issues with the criminal justice system, another influence on children and parents living together. They note that Black children lived in several different family structures. such as single-parent homes (some single persons live with an unmarried partner) and with extended families , grandparents, or kin. For pregnant Black people, prolonged stress has led to epigenetic changes causing higher incidences of preeclampsia , gestational diabetes , and maternal mortality in their population (Riggan et al., 2021). The nurse must recognize examples of racism and discrimination in the health-care system and become a change agent to overcome health inequities .
Immigrant and Migrant Families
Health-care access is limited for immigrant and migrant families. HealthCare.gov (n.d.) states that “lawfully present immigrants” can apply for the Health Insurance Marketplace, but undocumented immigrants are not eligible. Further eligibilities include living in the United States and not being incarcerated. Undocumented immigrants can be eligible for “emergency Medicaid” for prenatal care, depending on state regulations (Alarcon, 2022). Federally qualified health centers ( FQHC ) have bridged the gap for some immigrant families; FQHC’s mission is to serve those with limited access to health care and to improve the quality of life for millions, including immigrants (Alarcon, 2022).
Migrant families, like immigrant families, have limited access to health care. Many migrant families move from place to place for work. The frequent movement does not allow pregnant persons to receive consistent prenatal care, which can lead to poor outcomes for the person and their fetus. It is important for the nurse to determine all the previous providers for this pregnancy and request records to review all prenatal care.
LGBTQIA+ Families
LGBTQIA+ families are also at increased risk for domestic violence, discrimination, marginalization, and social exclusion. A study by Medina-Martínez et al. (2021) reveals that the LGBTQIA+ population has poorer physical and mental health and more depression, substance misuse, and suicide than the straight population. They also found higher incidences of colon, liver, breast, ovarian, and cervical cancers in lesbian and bisexual women. The study showed that many LGBTQIA+ people feel uncomfortable and unsafe in the health-care system because of discriminatory attitudes and practices. The health inequities/minority stress model proposes that adults from underrepresented groups who are socially stigmatized experience more stress and use maladaptive coping strategies, leading to rumination, substance misuse, and risky sexual behaviors (Medina-Martínez et al., 2021). Nurses can establish relationships with these patients by incorporating transcultural nursing interventions to help LGBTQIA+ families feel more included in and trusting of the health-care system.
People Who Are Incarcerated
In the United States, the rate of women who are incarcerated has dramatically increased to the second highest rate internationally, second only to Thailand (Friedman et al., 2023). The Friedman et al. (2023) study found that 75 percent of women who are incarcerated had children under 18 years old, and less than 33 percent of these children lived with their father during the mothers’ incarceration. They report that pregnant persons who are incarcerated have a higher risk of complications due to lack of prenatal care, trauma, poor nutrition, substance use, mental illness, chronic medical conditions, low socioeconomic status, and limited social support. Over the years, organizations such as ACOG, the Federal Bureau of Prisons , and the National Commission on Correctional Health Care have created standards for pregnant persons who are incarcerated, including the recommendation to allow patients to labor without restraints or shackles. Nurses caring for a laboring person who are incarcerated can provide nonjudgmental care and avoid discussing “taking the baby home.” Nurses can help the person work through feelings of sadness and grief over being separated from their baby.
Grandparents as Caretakers
A grandparent can become the primary caregiver to a grandchild for different reasons, such as premature death of the child’s parent or the parent’s incarceration, mental health issues, or substance use disorder. According to the 2017–2021 U.S. census, 7.1 million grandparents are living with and caring for grandchildren under the age of 18 (U.S. Census Bureau, n.d.). Of these grandparents rearing grandchildren, approximately 2.5 million of them may need to return to the workforce to provide for the grandchild (Saxena, 2021). Other challenges grandparents face include changes in family dynamics because the grandparent is now the disciplinarian; psychosocial impact because the grandparents and children are in different social groups with peers; lack of resources due to low income related to retirement or disability ; and challenges of parenting later in life, such as not having the energy to raise small children or discipline teens (Martin et al., 2020). Grandparents and grandchildren should receive resources for counseling for potential depression and financial resources.
Families with Lower Incomes
According to the National Health Council (Witting, 2023), 37.2 million Americans were living in poverty in 2020. Poverty causes poor health outcomes due to lack of available and quality health care for those who cannot afford reliable care. The National Health Council also noted that people living in poverty have more chronic diseases, such as heart, liver, and kidney disease. When people living in poverty could schedule health-care appointments, many times they did not have reliable transportation to get to the office (Witting, 2023). Pregnant persons living in poverty also have higher risk for poor outcomes owing to lack of prenatal care, poor nutrition, and stress (Witting, 2023). Nurses can provide supportive care while suggesting resources for the family to help with financial assistance.
Families Living in Rural Areas
Families living in rural areas in the United States face more health disparities than families living in urban areas. The CDC (2023) states that 46 million people in the United States live in a rural area. Areas without obstetric hospitals, birth centers, or obstetric providers are called maternity deserts (Treisman, 2022). These areas are mostly rural and have higher rates of maternal and newborn mortality than urban areas (Treisman, 2022). Statistics show that members of families living in rural areas have a higher risk of dying from heart disease, cancer, unintentional injury, chronic respiratory disease, and stroke than members of families living in urban areas (CDC, 2023). Children in rural areas are at risk for mental, behavioral, and developmental disorders. Some reasons for rural families’ increased risk of death from these diseases include long travel distance and time, higher rates of cigarette smoking, high blood pressure, obesity, higher rates of poverty, less access to health care, and more uninsured people (CDC, 2023). Nurses can address some of these issues when families who live in rural areas are present in the office or hospital. The nurse can educate the family on smoking cessation, weight loss, and increased physical activity, and can conduct recommended screenings for cancer. Some community-based mobile clinics can provide nursing care to these rural areas as well.
Social Determinants of Health of the Birthing Person and Newborn
The nonmedical factors that influence health outcomes, including conditions in which people are born, grow, work, live, and age, and the wider sets of forces and systems shaping the conditions of daily life are called the social determinants of health . Health outcomes impacted by social determinants of health are referred to as health disparities or health inequalities.
Various factors contribute to health inequalities among different cultural groups. Socioeconomic status, race, educational level, and physical proximity to health-care facilities are all causes of health inequalities. For example, Black and Native American populations have higher rates of obesity, diabetes, hypertension , and heart disease when compared to White populations (National Academies of Sciences, Engineering, and Medicine, 2017). The history of racism and discrimination in the medical system has resulted in widespread distrust, especially for Black, Indigenous, and Latinx populations. This distrust manifests in less seeking of care and a general skepticism of the care rendered. Nurses can perpetuate this distrust, or they can begin to heal these relationships by considering the patient’s background. If they practice trauma-informed care , they acknowledge all past and present parts of a person’s life situation, including any trauma they have endured (Center for Health Care Strategies, 2021) in an effort to provide treatment that supports the patient’s autonomy, strength, and control over making health-care decisions.
Several social determinants of health causing disparities in the care of the birthing person include financial barriers to health care, shortage of obstetric providers, prevalence of unhealthy behaviors (illicit drug and alcohol use; consumption of cheap, less nutritious foods), lack of equal education causing financial inequality, and racially segregated communities (Crear-Perry et al., 2021).
The Five Domains
The five domains of the social determinants of health include economic stability, education access and quality, health-care access and quality, neighborhood and built environment, and social and community context (Figure 2.4).
These five domains are the foundation of addressing inequities in education, economics, health care, communities, and neighborhoods.
Healthy People 2030
Healthy People 2030 is an initiative of the Office of Disease Prevention and Health Promotion of the U.S. Department of Health and Human Services. From its initial report in 1979 and its subsequent new iterations, it consists of national objectives aimed at improving health and well-being over the preceding decade. Social determinates of health are keys to creating the Healthy People objectives. Several objectives for pregnancy and childbirth include reducing preterm births, increasing the proportion of people who receive early and adequate prenatal care, increasing abstinence from alcohol during pregnancy, reducing pregnancy in adolescents, and reducing maternal deaths (U.S. Department of Health and Human Services, n.d.-b). (See Chapter 3 Health Promotion, Disease and Injury Prevention, and Well-Person Care for more discussion of Healthy People 2030.) The nurse can become active in professional organizations to help fulfill these objectives.
Caring for Patients Who Cannot Afford Their Necessary Health-Care/Prescriptions
The nurse is giving discharge instructions to a pregnant woman, describing how to take the prescribed medication. The woman quietly asks if it will hurt her baby if she does not take the medication. The nurse realizes the woman cannot afford the necessary medication. What can the nurse do?
When this situation occurs, the nurse can feel helpless and hopeless. The following suggestions can sometimes help in this situation.
- Ask the health-care provider if there is a less expensive medication that can be prescribed.
- Discuss drug assistance programs provided by many pharmaceutical companies, state programs, and nonprofit organizations.
- Contact the social services department to determine if the person qualifies for pregnancy Medicaid or other state and financial assistance.
- Recommend prescription assistance programs or websites such as GoodRx to find the lowest price for the medication.


11.2: Formation of Carbon-Carbon Bonds
Biocatalysts are turned out to be versatile catalysts for carbon-carbon bond forming and reduction reactions in organic synthesis.
Carbon-carbon bond formation belongs to the heart of organic synthesis. The biocatalyzed route provides effective tool for the construction of carbon-carbon with excellent enantioselectivity.
Hydrocyanation of Aldehydes
The biocatalytic hydrocyanation of aldehydes is one of the oldest methods in organic synthesis. One of the well-established technologies for the large-scale hydrocyanation of aldehydes is the oxynitrilase (Griengl process) catalyzed production of ( S )-phenoxybenzaldehyde cyanohydrins, which is an important intermediate for the industrial pyrethroid manufacture (Scheme \(\PageIndex{1}\)). This method is turned out to be useful for the reactions of numerous aldehydes.
Benzoin Condensation
The development of an asymmetric cross-benzoin condensation via enzymatic cross-coupling reactions is a synthetically useful process. Highly enantiomerically enriched mixed benzoins can be obtained from two different substituted benzaldehdyes using benzaldehyde lyase as a catalyst (Scheme \(\PageIndex{2}\)). One of the aldehydes acts as acceptor, whereas the other one acts as donor.
Aldol Reaction
The biocatalytic aldol reactions are highly specific with respect to donor component, whereas a broad substrate scope is observed for the acceptor molecules. One of the examples is the reaction of glycine (donor) with substituted benzaldehyde (acceptor) employing threonine aldolases to give α-amino β -hydroxy acids with excellent enantioselectivity (Scheme \(\PageIndex{3}\)).
Nitroaldol Reaction
Enzymes are also useful for the non-natural reactions. For example, using ( S )-oxynitrilase the reaction of nitromethane with a broad range of aldehydes can be accomplished with excellent enantioselectivity (Scheme \(\PageIndex{4}\)). Nitroalkane acts donor, whereas the aldehydes are acceptors.


26.5: Chapter Summary
This chapter provided an overview of the hypothalamus, pituitary gland, and adrenal cortex, which are essential components of the endocrine system. The hypothalamus is a small region of the brain that plays a key role in the regulation of many physiological processes in the body including hunger, thirst, and body temperature. It is also responsible for the regulation and release of pituitary hormones from the pituitary gland, which is sometimes referred to as the “master gland” because it controls the release of hormones from other endocrine glands. The adrenal cortex, part of the adrenal gland, is responsible for regulating fluid and electrolyte balance, glucose metabolism, adaptation to stress, and immune function.
This chapter covered drugs that are commonly used to treat conditions related to the hypothalamus, pituitary, and adrenal cortex. Overall, the hypothalamus, pituitary, and adrenal cortex play critical roles in the regulation of many physiological processes in the body. Disorders affecting the function of these structures can have significant impacts on health and well-being.


22.1: Introduction
From a fetal perspective, the process of birth is a crisis. In the womb, the fetus was snuggled in a soft, warm, dark, and quiet world. The placenta provided nutrition and oxygen continuously. Suddenly, the contractions of labor and vaginal childbirth forcibly squeeze the fetus through the birth canal, limiting oxygenated blood flow during contractions and shifting the skull bones to accommodate the small space. After birth, the newborn’s system must make drastic adjustments to a world that is colder, brighter, and louder, and where they will experience hunger and thirst. They first must successfully transition to a dry and inhospitable outside world. This includes regulating their own body temperature and breathing independently. It is critical for the nurse to understand the transition to extrauterine life.


21.0: Prelude to Organic Chemistry
All living things on earth are formed mostly of carbon compounds. The prevalence of carbon compounds in living things has led to the epithet “carbon-based” life. The truth is we know of no other kind of life. Early chemists regarded substances isolated from organisms (plants and animals) as a different type of matter that could not be synthesized artificially, and these substances were thus known as organic compounds . The widespread belief called vitalism held that organic compounds were formed by a vital force present only in living organisms. The German chemist Friedrich Wohler was one of the early chemists to refute this aspect of vitalism, when, in 1828, he reported the synthesis of urea, a component of many body fluids, from nonliving materials. Since then, it has been recognized that organic molecules obey the same natural laws as inorganic substances, and the category of organic compounds has evolved to include both natural and synthetic compounds that contain carbon. Some carbon-containing compounds are not classified as organic, for example, carbonates and cyanides, and simple oxides, such as CO and CO 2 . Although a single, precise definition has yet to be identified by the chemistry community, most agree that a defining trait of organic molecules is the presence of carbon as the principal element, bonded to hydrogen and other carbon atoms.
Figure 20.0.1: All organic compounds contain carbon and most are formed by living things, although they are also formed by geological and artificial processes. (credit left: modification of work by Jon Sullivan; credit left middle: modification of work by Deb Tremper; credit right middle: modification of work by “annszyp”/Wikimedia Commons; credit right: modification of work by George Shuklin)
Today, organic compounds are key components of plastics, soaps, perfumes, sweeteners, fabrics, pharmaceuticals, and many other substances that we use every day. The value to us of organic compounds ensures that organic chemistry is an important discipline within the general field of chemistry. In this chapter, we discuss why the element carbon gives rise to a vast number and variety of compounds, how those compounds are classified, and the role of organic compounds in representative biological and industrial settings.
Contributors
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Paul Flowers (University of North Carolina - Pembroke), Klaus Theopold (University of Delaware) and Richard Langley (Stephen F. Austin State University) with contributing authors. Textbook content produced by OpenStax College is licensed under a Creative Commons Attribution License 4.0 license. Download for free at<EMAIL_ADDRESS>).


22.7: Speciation and Extinction Through Time
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- Last updated
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History of life as revealed by the fossil record
With help from molecular phylogenies:
| Eras | Periods | Epochs | Aquatic Life | Terrestrial Life |
|---|---|---|---|---|
| With approximate starting dates in millions of years ago in parentheses. Geologic features in green | ||||
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Cenozoic (66)
The "Age of Mammals" |
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| Quaternary (2.6) | Holocene | Humans in the new world | ||
| Pleistocene | Periodic glaciation | First humans | ||
| Continental drift continues | ||||
| Neogene (23) | Pliocene | Atmospheric oxygen reaches today's level (21%) | Hominids | |
| Miocene | Adaptive radiation of birds, continued radiation of mammals | |||
| Paleogene (66) | Oligocene | All modern groups present | ||
| Eocene | ||||
| Paleocene | ||||
|
Mesozoic (251)
The "Age of Reptiles" |
Cretaceous (146) | Still attached: N. America & N. Europe; Australia & Antarctica ; Mass extinction of both aquatic and terrestrial life at the end | ||
| Modern bony fishes | Extinction of dinosaurs and pterosaurs; first snakes | |||
| Extinction of ammonites, plesiosaurs, ichthyosaurs | Rise of angiosperms | |||
| Africa & S. America begin to drift apart | ||||
| Jurassic (200) | Plesiosaurs, ichthyosaurs abundant; first diatoms | Archaeopteryx ; dinosaurs dominant but mammals (Eutheria) begin to diversify | ||
| Ammonites again abundant | First lizards | |||
| Skates, rays, and bony fishes abundant | Adaptive radiation of dinosaurs | |||
| Pangaea splits into Laurasia and Gondwana; atmospheric oxygen drops to ~13% | ||||
| Triassic (251) | Mass extinctions at the end. |
Mass extinctions at the end.
First mammals Adaptive radiation of reptiles: thecodonts, therapsids, turtles, crocodiles, first dinosaurs |
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| Ammonites abundant at first | ||||
| Rise of bony fishes | ||||
| Paleozoic (542) | Permian (299) | Periodic glaciation and arid climate; atmospheric oxygen reaches ~30%. Volcanic eruptions killed off 90% of marine species at end. | ||
| Extinction of trilobites | Reptiles abundant. Cycads, conifers, ginkgos | |||
| Pennsylvanian (320) |
Warm, humid climate
Together the Pennsylvanian and Mississippian make up the "Carboniferous"; also called the "Age of Amphibians" |
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| Ammonites, bony fishes |
First reptiles
Coal swamps |
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| Mississippian (359) | Adaptive radiation of sharks |
Forests of lycopsids, sphenopsids, and seed ferns
Amphibians abundant Adaptive radiation of the insects (Hexapoda) |
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| Atmospheric oxygen begins to rise as organic matter is buried, not respired | ||||
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Devonian (416)
The "Age of Fishes" |
Extensive inland seas | Cartilaginous and bony fishes abundant. Ammonites, nautiloids, ostracoderms, eurypterids |
Ferns, lycopsids, and sphenopsids
First gymnosperms First amphibians |
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| Silurian (443) | Mild climate; inland seas | First bony fishes | First myriapods and chelicerates | |
| Ordovician (485) | Mild climate, inland seas | Trilobites abundant |
Fungi present
First plants (liverworts?) First insects |
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| Cambrian (541) |
First vertebrates (jawless fishes). Eurypterids, crustaceans
mollusks, echinoderms, sponges, cnidarians, annelids, and tunicates present. Trilobites dominant. |
No fossils of terrestrial eukaryotes, but phylogenetic trees suggest that lichens, mosses, perhaps even vascular plants were present. | ||
| Periodic glaciation | ||||
| Proterozoic (2500) |
Ediacaran
(635) |
Fossil evidence of multicellular algae, fungi, and bilaterian invertebrates | ||
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Evidence of eukaryotes
~1.8 x10 9 years ago |
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| Archaean (3600) |
Evidence of archaea and bacteria
~3.5 x10 9 years ago |
The Geologic and Evolutionary Record
A remarkable feature of the table above is how often evolutionary changes coincided with geologic changes on the earth. But consider that changes in geology (e.g., mountain formation or lowering of the sea level) cause changes in climate, and together these alter the habitats available for life. Two types of geologic change seem to have had especially dramatic effects on life: continental drift and the impact of asteroids
Continental Drift
A body of evidence, both geological and biological, supports the conclusion that 200 million years ago, at the start of the Mesozoic era , all the continents were attached to one another in a single land mass, which has been named Pangaea . This drawing of Pangaea (adapted from data of R. S. Dietz and J. C. Holden) is based on a computer-generated fit of the continents as they would look if the sea level were lowered by 6000 feet (~1800 meters). During the Triassic , Pangaea began to break up, first into two major land masses:
- Laurasia in the Northern Hemisphere
- Gondwana in the Southern Hemisphere.
The present continents separated at intervals throughout the remainder of the Mesozoic and through the Cenozoic, eventually reaching the positions they have today. Let us examine some of the evidence.
Shape of the Continents
The east coast of South America and the west coast of Africa and are strikingly complementary. This is even more dramatic when one tries to fit the continents together using the boundaries of the continental slopes, e.g., 6000 feet (~1800 meters) down, rather than the shorelines.
Geology
- In both mineral content and age, the rocks in a region on the east coast of Brazil match precisely those found in Ghana on the west coast of Africa.
- The low mountain ranges and rock types in New England and eastern Canada appear to be continued in parts of Great Britain, France, and Scandinavia.
- India and the southern part of Africa both show evidence of periodic glaciation during Paleozoic times (even though both are now close to the equator). The pattern of glacial deposits in the two regions not only match each other but also glacial deposits found in South America, Australia, and Antarctica.
Fossils
- Fossil reptiles found in South Africa are also found in Brazil and Argentina.
- Fossil amphibians and reptiles found in Antarctica are also found in South Africa, India, and China.
- Most of the marsupials alive today are confined to South America and Australia. But if these two continents were connected by Antarctica in the Mesozoic, one might expect to find fossil marsupials there. In March 1982, this prediction was fulfilled with the discovery in Antarctica of the remains of Polydolops , a 9-ft (2.7 m) marsupial.
The Impact Hypothesis
The Cretaceous period, the last period of the Mesozoic, marked the end of the Age of Reptiles. It was followed by the Cenozoic era, the Age of Mammals. Although extinctions have occurred throughout the history of life, an extraordinary number of them occurred in a relatively brief period at the end of the Cretaceous. Why?
The Alvarez Theory
Louis Alvarez, his son Walter, and their colleagues proposed that a giant asteroid or comet striking the earth some 66 million years ago caused the massive die-off at the end of the Cretaceous. Presumably, the impact generated so much dust and gases that skies were darkened all over the earth, photosynthesis declined, and worldwide temperatures dropped. The outcome was that as many as 75% of all species — including all dinosaurs — became extinct.
The key piece of evidence for the Alvarez hypothesis was the finding of thin deposits of clay containing the element iridium at the interface between the rocks of the Cretaceous and those of the Paleogene period (called the K-Pg boundary after the German word for Cretaceous). Iridium is a rare element on earth (although often discharged from volcanoes), but occurs in certain meteorites at concentrations thousands of times greater than in the earth's crust.
After languishing for many years, the Alvarez theory gained strong support from the discovery in the 1990s of the remains of a huge (180 km in diameter) crater in the Yucatan Peninsula that dated to 65 million years ago.
The abundance of sulfate-containing rock in the region suggests that the impact generated enormous amounts of sulfur dioxide (SO 2 ), which later returned to earth as a bath of acid rain. A smaller crater in Iowa, formed at the same time, many have contributed to the devastation. Perhaps during this period the earth passed through a swarm of asteroids or a comet and the repeated impacts made the earth uninhabitable for so many creatures of the Mesozoic.
Other Impacts
A mass extinction of non-dinosaur reptiles occurred earlier, at the end of the Triassic . It was followed by a great expansion in the diversity of dinosaurs. The recent discovery of a layer enriched in iridium in rocks formed at the boundary between the Triassic and Jurassic suggests that impact from an asteroid or comet may have been responsible then just as it was at the K-Pg boundary.
The largest extinction of all time occurred still earlier at the end of the Permian period. There is evidence off the coast of Australia that a huge impact there may have contributed to the extinctions at the Permian-Triassic (P-T) boundary.


5.8: Expressing Possession in Hindi
Expressing Possession Video
Instructor Video: Expressing Possession in Hindi
In English, we you “to have” to express possession.
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For examples:
I have a car.
I have two sisters.
I have a fever.
This book has several chapters.
In Hindi, there are four different ways to express possession “to have.” It depends on a thing that is being possessed.
| In Hindi | Uses | Examples | |
| To have | के पास | It is used to express possession of those inanimate things of which the ownership is not necessarily permanent, and are tangible, movable and material objects. |
मेरे पास बहुत किताबें हैं | “I have many books.”
क्या आपके पास कुछ पैसे हैं ? “Do you have some money?” |
| का/के/की |
का, के, की are used to express
possession of kin, limbs of the body and also permanent/legal possessions such as land etc. |
मेरा एक भाई है | I have a brother.”
आपकी दो सुन्दर आँखें हैं | “S/he has two beautiful eyes.” |
|
| को |
को is used to show possession of
abstract entity could be (a) Physical ailments such as fever, cold, cough, headache, etc. (b) Free time or work, and (c) Need. |
उसको तेज़ बुख़ार है | “S/he has high fever.”
मुझे बहुत काम है | “I have lots of work.” |
|
| में | में is used to show possession of an integral part of a whole in Hindi. |
मेरे घर में, चार कमरे हैं | My home has four rooms.”
मेरे स्कूल में, पच्चीस अध्यापक हैं | My school has 25 teachers.” |
Activity
Please choose the correct form of subject to express possession in Hindi.
https://openbooks.lib.msu.edu/ll151/?p=882
धन्यवाद !


9.2: pH and pOH
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Harper College Chemistry Department
As discussed earlier, hydronium and hydroxide ions are present both in pure water and in all aqueous solutions, and their concentrations are inversely proportional as determined by the ion product of water ( K w ). The concentrations of these ions in a solution are often critical determinants of the solution’s properties and the chemical behaviors of its other solutes, and specific vocabulary has been developed to describe these concentrations in relative terms. A solution is neutral if it contains equal concentrations of hydronium and hydroxide ions; acidic if it contains a greater concentration of hydronium ions than hydroxide ions; and basic if it contains a lesser concentration of hydronium ions than hydroxide ions.
A common means of expressing quantities, the values of which may span many orders of magnitude, is to use a logarithmic scale. One such scale that is very popular for chemical concentrations and equilibrium constants is based on the p-function, defined as shown where “X” is the quantity of interest and “log” is the base-10 logarithm:
The pH of a solution is therefore defined as shown here, where [H 3 O + ] is the molar concentration of hydronium ion in the solution:
Rearranging this equation to isolate the hydronium ion molarity yields the equivalent expression:
Likewise, the hydroxide ion molarity may be expressed as a p-function, or pOH:
or
Finally, the relation between these two ion concentration expressed as p-functions is easily derived from the K w expression:
K W = [H 3 O + ][OH-]
-log K W = -log([H 3 O + ][OH – ]) = -log[H 3 O + ] + -log[OH – ]
pK W = pH + pOH
At 25 °C, the value of K w is 1.0×10 −14 , and so:
As was shown in [link] , the hydronium ion molarity in pure water (or any neutral solution) is 1.0 × 10 −7 M at 25 °C. The pH and pOH of a neutral solution at this temperature are therefore:
pH = -log[H 3 O + ] = -log(1.0×10 -7 ) = 7
pOH = -log[OH – ] = -log(1.0×10 -7 ) = 7
And so, at this temperature , acidic solutions are those with hydronium ion molarities greater than 1.0 × × 10 −7 M and hydroxide ion molarities less than 1.0 × 10 −7 M (corresponding to pH values less than 7.00 and pOH values greater than 7.00). Basic solutions are those with hydronium ion molarities less than 1.0 × 10 −7 M and hydroxide ion molarities greater than 1.0 × 10 −7 M (corresponding to pH values greater than 7.00 and pOH values less than 7.00).
Since the autoionization constant K w is temperature dependent, these correlations between pH values and the acidic/neutral/basic adjectives will be different at temperatures other than 25 °C. For example, the “Check Your Learning” exercise accompanying [link] showed the hydronium molarity of pure water at 80 °C is 4.9 × 10 −7 M , which corresponds to pH and pOH values of 6.31.
At this temperature, then, neutral solutions exhibit pH = pOH = 6.31, acidic solutions exhibit pH less than 6.31 and pOH greater than 6.31, whereas basic solutions exhibit pH greater than 6.31 and pOH less than 6.31. This distinction can be important when studying certain processes that occur at nonstandard temperatures, such as enzyme reactions in warm-blooded organisms. Unless otherwise noted, references to pH values are presumed to be those at standard temperature (25 °C) ( Table ).
| Table: Summary of Relations for Acidic, Basic and Neutral Solutions | ||
|---|---|---|
| Classification | Relative Ion Concentrations | pH at 25 °C |
| acidic | [H 3 O + ] > [OH − ] | pH < 7 |
| neutral | [H 3 O + ] = [OH − ] | pH = 7 |
| basic | [H 3 O + ] < [OH − ] | pH > 7 |
Figure 1 shows the relationships between [H 3 O + ], [OH − ], pH, and pOH, and gives values for these properties at standard temperatures for some common substances.
Calculation of pH from [H 3 O + ]
What is the pH of stomach acid, a solution of HCl with a hydronium ion concentration of 1.2 × 10 −3 M ?
Solution
(The use of logarithms is explained in Appendix B . Recall that, as we have done here, when taking the log of a value, keep as many decimal places in the result as there are significant figures in the value.)
Check Your Learning
Water exposed to air contains carbonic acid, H 2 CO 3 , due to the reaction between carbon dioxide and water:
Air-saturated water has a hydronium ion concentration caused by the dissolved CO 2 of 2.0 × 10 −6 M , about 20-times larger than that of pure water. Calculate the pH of the solution at 25 °C.
Calculation of Hydronium Ion Concentration from pH
Calculate the hydronium ion concentration of blood, the pH of which is 7.3 (slightly alkaline).
Solution
(On a calculator take the antilog, or the “inverse” log, of −7.3, or calculate 10 −7.3 .)
Check Your LearningCalculate the hydronium ion concentration of a solution with a pH of −1.07.
12 M
Normal rainwater has a pH between 5 and 6 due to the presence of dissolved CO 2 which forms carbonic acid:
$\ce {CO_2(g) + H_2O(l) <=> H_2CO_3(aq) <=> H^+(aq) + HCO_3^-(aq)}$
Acid rain is rainwater that has a pH of less than 5, due to a variety of nonmetal oxides, including CO 2 , SO 2 , SO 3 , NO, and NO 2 being dissolved in the water and reacting with it to form not only carbonic acid, but sulfuric acid and nitric acid. The formation and subsequent ionization of sulfuric acid are shown here:
Carbon dioxide is naturally) present in the atmosphere because we and most other organisms produce it as a waste product of metabolism. Carbon dioxide is also formed when fires release carbon stored in vegetation or when we burn wood or fossil fuels. Sulfur trioxide in the atmosphere is naturally produced by volcanic activity, but it also stems from burning fossil fuels, which have traces of sulfur, and from the process of “roasting” ores of metal sulfides in metal-refining processes. Oxides of nitrogen are formed in internal combustion engines where the high temperatures make it possible for the nitrogen and oxygen in air to chemically combine.
Acid rain is a particular problem in industrial areas where the products of combustion and smelting are released into the air without being stripped of sulfur and nitrogen oxides. In North America and Europe until the 1980s, it was responsible for the destruction of forests and freshwater lakes, when the acidity of the rain actually killed trees, damaged soil, and made lakes uninhabitable for all but the most acid-tolerant species. Acid rain also corrodes statuary and building facades that are made of marble and limestone ( Figure 2 ). Regulations limiting the amount of sulfur and nitrogen oxides that can be released into the atmosphere by industry and automobiles have reduced the severity of acid damage to both natural and manmade environments in North America and Europe. It is now a growing problem in industrial areas of China and India.
For further information on acid rain, visit this website hosted by the US Environmental Protection Agency.
Calculation of pOH
What are the pOH and the pH of a 0.0125 M solution of potassium hydroxide, KOH?
Solution
Potassium hydroxide is a highly soluble ionic compound and completely dissociates when dissolved in dilute solution, yielding [OH − ] = 0.0125 M :
The pH can be found from the pOH:
Check Your Learning
The hydronium ion concentration of vinegar is approximately 4 × 10 −3 M . What are the corresponding values of pOH and pH?
pOH = 11.6, pH = 2.4
The acidity of a solution is typically assessed experimentally by measurement of its pH. The pOH of a solution is not usually measured, as it is easily calculated from an experimentally determined pH value. The pH of a solution can be directly measured using a pH meter ( Figure 3 ).
The pH of a solution may also be visually estimated using colored indicators ( Figure 4 ).
Key Concepts and Summary
The concentration of hydronium ion in a solution of an acid in water is greater than 1.0 × 10 −7 M at 25 °C. The concentration of hydroxide ion in a solution of a base in water is greater than 1.0 × 10 −7 M at 25 °C. The concentration of H 3 O + in a solution can be expressed as the pH of the solution; pH = −log[H 3 O + ] . The concentration of OH − can be expressed as the pOH of the solution: pOH = −log[OH − ]. In pure water, pH = 7.00 and pOH = 7.00
Key Equations
- pH = -log[H 3 O + ]
- pOH = −log[OH − ]
- [H 3 O + ] = 10 −pH
- [OH − ] = 10 −pOH
- pH + pOH = p K w = 14.00 at 25 °C
Chemistry End of Chapter Exercises
1. Explain why a sample of pure water at 40 °C is neutral even though [H 3 O + ] = 1.7 × 10 −7 M . K w is 2.9 × 10 −14 at 40 °C.
2. The ionization constant for water ( K w ) is 2.9 × 10 −14 at 40 °C. Calculate [H 3 O + ], [OH − ], pH, and pOH for pure water at 40 °C.
3. The ionization constant for water ( K w ) is 9.311 × 10 −14 at 60 °C. Calculate [H 3 O + ], [OH − ], pH, and pOH for pure water at 60 °C.
4. Calculate the pH and the pOH of each of the following solutions at 25 °C for which the substances ionize completely:
(a) 0.200 M HCl
(b) 0.0143 M NaOH
(c) 3.0 M HNO 3
(d) 0.0031 M Ca(OH) 2
5. Calculate the pH and the pOH of each of the following solutions at 25 °C for which the substances ionize completely:
(a) 0.000259 M HClO 4
(b) 0.21 M NaOH
(c) 0.000071 M Ba(OH) 2
(d) 2.5 M KOH
6. What are the pH and pOH of a solution of 2.0 M HCl, which ionizes completely?
7. What are the hydronium and hydroxide ion concentrations in a solution whose pH is 6.52?
8. Calculate the hydrogen ion concentration and the hydroxide ion concentration in wine from its pH. See Figure 1 for useful information.
Calculate the hydronium ion concentration and the hydroxide ion concentration in lime juice from its pH. See Figure 1 for useful information.
9. The hydronium ion concentration in a sample of rainwater is found to be 1.7 × 10 −6 M at 25 °C. What is the concentration of hydroxide ions in the rainwater?
10. The hydroxide ion concentration in household ammonia is 3.2 × 10 −3 M at 25 °C. What is the concentration of hydronium ions in the solution?
Glossary
- acidic
- describes a solution in which [H 3 O + ] > [OH − ]
- basic
- describes a solution in which [H 3 O + ] < [OH − ]
- neutral
- describes a solution in which [H 3 O + ] = [OH − ]
- pH
- logarithmic measure of the concentration of hydronium ions in a solution
- pOH
- logarithmic measure of the concentration of hydroxide ions in a solution


11.2: Merchandise Allocations
Learning OUTCOME
- Describe how retailers decide on merchandise allocations.
Merchandise allocation is the process of determining how to distribute merchandise to individual store units for maximum sales and minimal markdowns. Depending on the size and sophistication of the retail operation, this can be a simple process, or an extremely complex algorithmic exercise. Some retailers plan their season’s purchases from the ground up based on ideal store allocation, or others use the allocation process to break down merchandise receipts to allocate to online warehouse distribution, regional distribution centers or direct to stores.
In additional to the math of the process, there are strategic and tactical considerations for merchandise allocation as well. Stores in their “grand opening” phase will receive maximum merchandise allocation to both make an impact to new customers and to help determine the sales potential of the new store unit for future allocation accuracy. Allocation can also be influenced by a competitive strategy where a retailer is attempting to make a “show of strength” with wide assortments and deep quantities for a more favorable impression when compared their competitors inventory position.
As you would imagine, commercial software applications have been developed to assist retailers in the computational-heavy process of merchandise allocation. Vendors such as JustEnough, RELEX, Logility, JDA Software, Oracle, and many others compete in this space. Here are some screen shots of a package from JustEnough , to give you an idea of the capabilities of these applications.
In the first, screen shot you can see the individual store locations broken out and the allocation percentages listed based on performance metrics. The second screen shot is more focused on a category of merchandise grouped by style with exception reporting enabled.
Practice Questions
Contributors and Attributions
- Merchandise Allocations. Authored by : Robert Danielson. Provided by : Lumen Learning. License : CC BY: Attribution


16.17: OSHA Penalties
- Describe how OSHA penalties are determined
OSHA penalties are determined by the type of violation, as illustrated in Table 1. Violation types range in significant/penalty from minor (posting requirements) to willful or repeated. In settling a penalty, OSHA has a policy of reducing penalties for small employers and those acting in good faith. For serious violations, OSHA may also reduce the proposed penalty based on the gravity of the alleged violation. No good faith adjustment will be made for alleged willful (intentional) violations. States that operate their own Occupational Safety and Health Plans are required to adopt maximum penalty levels that are at least as effective as Federal OSHA’s.
| Type of Violation | Penalty |
|---|---|
|
Serious
Other-Than-Serious Posting Requirements |
$13,260 per violation |
| Failure to Abate | $13,260 per day beyond the abatement date |
| Willful or Repeated | $132,598 per violation |
For perspective on actual penalties assessed, see OSHA’s top penalties by state page, that provides a clickable map of enforcement cases with initial penalties of $40,000 or more. A repeat offender: the U.S. Postal Service (USPS); the most recent violation was 6/13/19 (San Francisco), with a $85,248 penalty. Also on the list: Tesla, Inc. with a $82,000 penalty on 2/28/2019, Skechers USA, Inc. with a $42,370 penalty on 12/14/2018 and
Southern California Edison, with a $95,435 penalty on 11/19/2018. Ironically, Aerotek, Inc.—“the leading recruitment and staffing agency…focused on bringing great people and great organizations together” [2] – was fined $55,010 on 4/23/19.
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"
OSHA Penalties
." Occupational Safety and Health Administration, United States Department of Labor. Accessed August 20, 2019. ↵
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"
Aerotek Recruiting and Staffing
." Accessed August 20, 2019. ↵


1.6: Benzene and Conjugation
- Understanding and naming benzene derivatives.
Aromatic hydrocarbons, like this benzene ring, have unexpected chemistry.
We would expect to name this molecule 1,3,5-cyclohexatriene and see its double bonds react like other double bonds. However, these double bonds do not react in the same way as double bonds in a standard alkene. Observe the result of the below experiment under the appropriate reaction conditions.
This surprising stability of the double bonds in the benzene ring is not due to the cyclic arrangement of the carbon chain. Under the appropriate reaction conditions, we see the following results for adding hydrogen across the double bonds of the molecules below.
Measuring the bond lengths gives the following result.
| Bond Type | Bond Length (Angstroms) |
|---|---|
| Single | 1.54 |
| Double | 1.34 |
| Benzene | 1.4 |
Therefore, the three “double bonds” of the benzene ring are not true double bonds. The electrons are shared across all of the carbons in the ring, an arrangement called conjugation which is better represented by the below structure.
When depicting benzene rings using the double bond drawing, remember that the ring is a hybrid between two equally likely resonance structures.
Therefore both structures below would be named 1-chlorobenzene.
When a benzene ring has two substituents , they are named based upon their position to each other rather than by numbers.
1. What is the name of Molecule A?
2. A benzene ring can be a substituent.
The name of this molecule is 2-phenyldecane.
What is the name of Molecule B?
Conjugation is not limited to cyclic structures. One of the two molecules below does not react with halogen halides under standard reaction conditions. Which molecule do you predict is the more stable one? Why? What prediction would you make about the lengths of its carbon-carbon bonds?
- Write the steps that you use to name a benzene derivative or a molecule containing a benzene ring as a substituent, in order, as instructions for a student who doesn't know how to do it.
- Draw any benzene-containing molecule and go through the steps in naming your molecule.


1.4.S: Stoichiometry of Chemical Reactions (Summary)
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- atoms are neither created nor destroyed during any chemical reaction
- stoichiometry – quantitative nature of chemical formulas and chemical reactions
3.1: Chemical Equations
A chemical reaction is described by a chemical equation that gives the identities and quantities of the reactants and the products. In a chemical reaction, one or more substances are transformed to new substances. A chemical reaction is described by a chemical equation, an expression that gives the identities and quantities of the substances involved in a reaction. A chemical equation shows the starting compound(s)—the reactants—on the left and the final compound(s)—the products—on the right.
- chemical equations – the way chemical reactions are represented
- reactants – starting substances
- products – substances produced from a reaction
- balanced equation – equation with equal atoms on both sides of the equation
- subscripts should never be changed in balancing an equation
- coefficients changes only the amount and not identity of the substance
3.2: Some Simple Patterns of Chemical Reactivity
By recognizing general patterns of chemical reactivity, you will be able to successfully predict the products formed by a given combination of reactants We can often predict a reaction if we have seen a similar reaction before.
3.2.1 Using the Periodic Table
- periodic table can be used to determine reactivity of substances
- all alkali metals react with water to form their hydroxide compounds and hydrogen
3.2.2 Combustion in Air
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- rapid reaction that produces a flame
- most combustion reactions in air involve oxygen
- hydrocarbons and related compounds produce CO 2 and H 2 O during combustion
3.2.3 Combination and Decomposition Reactions
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- combination reactions two or more substances react to form one product
- decomposition reaction one substance produces two or more substances
3.3: Formula Masses
The empirical formula of a substance can be calculated from its percent composition, and the molecular formula can be determined from the empirical formula and the compound’s molar mass. The empirical formula of a substance can be calculated from the experimentally determined percent composition, the percentage of each element present in a pure substance by mass. In many cases, these percentages can be determined by combustion analysis.
3.3.1 The Atomic Mass Scale
- atomic mass unit (amu) – unit in measuring mass of atoms
- 1 amu = 1.66054*10 - 24 g and 1 amu = 6.02214*10 24 amu
3.3.2 Average Atomic Masses
- atomic weight – average atomic mass
3.3.3 Formula and Molecular Weights
- formula weight – sum of the atomic weights of each atom in its chemical formula
- molecular weight – same as formula weight
3.3.4 Percentage composition from Formulas
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- ((atoms of element)(AW)/(FW of compound) * 100
3.3.5 The Mole
- avogadro’s number – 6.02*10 23 atoms
- molar mass – numerically equal to its formula weight
- grams <use molar mass> moles <use avogadro’s number> molecules
3.5: Empirical Formulas from Analysis
Molecular formulas tell you how many atoms of each element are in a compound, and empirical formulas tell you the simplest or most reduced ratio of elements in a compound. If a compound's molecular formula cannot be reduced any more, then the empirical formula is the same as the molecular formula. Combustion analysis can determine the empirical formula of a compound, but cannot determine the molecular formula (other techniques can though).
- empirical formula gives relative number of atoms in each element
- mass % elements >>> assume 100g sample >>> grams of each element >>> use atomic weights >>> moles of each element >>> calculate mole ratio >>> empirical formula
- "percent to mass, mass to mol, divide by small, multiply ‘til whole/"
3.5.1 Molecular Formula from Empirical Formula
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- the subscripts in the molecular formula of a substance are always a whole-number multiple of the corresponding subscripts in its empirical formula
3.5.2 Combustion Analysis
3.6: Quantitative Information from Balanced Equations
Either the masses or the volumes of solutions of reactants and products can be used to determine the amounts of other species in the balanced chemical equation. Quantitative calculations that involve the stoichiometry of reactions in solution use volumes of solutions of known concentration instead of masses of reactants or products. The coefficients in the balanced chemical equation tell how many moles of reactants are needed and how many moles of product can be produced.
- the coefficients in a balanced chemical equation can be interpreted both as the relative numbers of molecules involved in the reaction and as the relative numbers of moles
- stoichiometrically equivalent quantities
- grams reactant >> moles reactant >> moles product >> grams product
- grams of substance A >> use molar mass of A >> moles of substance A >> use coefficients of A and B from balanced equation >> moles of substance B >> use molar mass of B >> grams of substance B
3.7: Limiting Reactants
The stoichiometry of a balanced chemical equation identifies the maximum amount of product that can be obtained. The stoichiometry of a reaction describes the relative amounts of reactants and products in a balanced chemical equation. A stoichiometric quantity of a reactant is the amount necessary to react completely with the other reactant(s). If a reactant remains unconsumed after complete reaction has occurred, it is in excess. The reactant that is consumed first is the limiting reagent.
- limiting reactant – limits the amount of product formed
3.7.1 Theoretical Yields
- theoretical yield – the amount of product that is calculated to form
- actual yield – the amount of product actually formed
\[ \text{percent yield} = \dfrac{\text{actual yield}}{\text{theoretical yield}} \times 100\% \nonumber \]


6.1: Prewriting Strategies
The term “pre-writing” conjures up a lot of strange activities and practices. You’ve probably tried many different prewriting strategies in the past, and may have a good idea of what works for you and what doesn’t. Keep in mind, that the KIND of writing project you’re working on can impact how effective a particular technique is to use in a given situation.
Some resources for additional prewriting activities are listed here.
FREEWRITING
Figure \(\PageIndex{1}\)
Setting a goal for a short amount of time (5 minutes or 10 minutes are good options), just write anything that comes to mind related to your topic. The goal is to not worry about what comes out of your pen, if handwriting, or keyboard, if typing. Instead, just free your mind to associate as it wishes. It’s amazingly productive for rich ideas, and it’s nice not to have to worry about spelling and grammar.
Additional information: About.com’s “How to FreeWrite”
LIST-MAKING
Figure \(\PageIndex{2}\)
If you’re a list-maker by nature, there’s no reason not to harness that for academic writing purposes. Jot notes about major ideas related to the subject you’re working with. This also works well with a time limit, like 10 minutes. Bonus points–after you’ve had time to reflect on your list, you can rearrange it in hierarchical order, and create a basic outline quite simply.
Additional Information: Higher Awareness’s “List Making – Journaling Tool”
CLUSTERING
Figure \(\PageIndex{3}\)
Also known as “mapping,” this is a more visual form of brainstorming. It asks you to come up with topic ideas, and draw lines to connect ideas and figure out sub-categories and related ideas. You can end up with a quite extensive “bubble cloud” as a result. This also works well within a time limit, like 10 minutes.
Additional Information: Edudemic’s 5 Innovative Mind-Mapping Tools for Education
QUESTIONING
Figure \(\PageIndex{4}\)
The way to find answers is to ask questions—seems simple enough. This applies to early-stage writing processes, just like everything else. When you have a topic in mind, asking and answering questions about it is a good way to figure out directions your writing might take.
Additional Information: Paradigm’s The Journalists’ Questions (7 pages)
Other prewriting strategies exist. Do you have a favorite method?


7.9: Glossary
Abnormal vaginal bleeding (ăb-nŏr-măl vă-jĭ-năl blēd-ing): Unusual bleeding from the vagina, including very heavy menstrual flow, bleeding between cycles, or prolonged bleeding. (Chapter 7.6)
Adenocarcinoma in situ (ăd-ĕ-nō-kăr-sĭ-NŌ-mă ĭn SĪ-tū): A condition where advanced, precancerous cells are found in the glandular tissue of the cervix. (Chapter 7.6)
Adnexa (ăd-NĔK-să): The accessory structures of the uterus, including the fallopian tubes and ovaries. (Chapter 7.5)
Amenorrhea (ā-men-ŏ-RĒ-ă): The absence of menstrual flow. (Chapter 7.5)
Anovulation (an-ov-yŭ-LĀ-shŏn): The absence of ovulation when an egg is not released from the ovaries. (Chapter 7.5)
Bartholin’s glands (BAR-tō-lĭns glăns): Glands that secrete mucus to keep the vestibular area moist, located near the vaginal opening. (Chapter 7.4)
Bilateral oophorectomy (bī-LĂT-ĕr-ăl ō-ŏ-fŏ-REK-tŏ-mē): Removal of both ovaries. (Chapter 7.7)
Bilateral salpingo-oophorectomy (bī-LĂT-ĕr-ăl săl-pĭng-gō-ō-ŏ-fŏ-REK-tŏ-mē): Removal of both ovaries and both Fallopian tubes. (Chapter 7.7)
Biopsy (BĪ-ŏp-sē): A diagnostic procedure where tissue, fluid, or lymph nodes are removed for examination under a microscope. (Chapter 7.6)
Breast cancer (brest KAN-sĕr): Malignant tumors developing from breast tissue cells. (Chapter 7.6)
Breast-conserving surgery (brĕst kŏn-sĕr-vĭng sŭr-jĕr-ē): Surgical procedure removing only the cancerous part of the breast, not the entire breast.  (Chapter 7.6)
Breast ultrasound (brĕst ŭl-tră-sound): A diagnostic imaging technique using sound waves to create images of the breast tissue. (Chapter 7.6)
Cervical cancer (SĔR-vi-kăl KAN-sĕr): Cancer arising from the cervix, often associated with human papillomavirus (HPV) infection. (Chapter 7.6)
Cervix (SĔR-vĭks): The lower part of the uterus, connecting the uterus to the vagina. (Chapter 7.4)
Chemotherapy (kē-mō-THĔR-ă-pē): The use of drugs to destroy or inhibit the growth of cancerous cells.  (Chapter 7.4)
Cold knife conization (kŏn-Ī-ZĀ-shŏn): A procedure using a scalpel or laser to remove a cone-shaped section of abnormal cervical tissue. (Chapter 7.6)
Colposcopy (kŏl-PŎS-kō-pē): A procedure using a lighted magnifying instrument to examine the cervix and potentially remove tissue for biopsy. (Chapter 7.6)
Conception (kŏn-sĕp-shŏn): The process of a sperm fertilizing an ovum, forming a zygote. (Chapter 7.5)
Contraception (kon-tră-SEP-shŏn): Methods or devices used to prevent pregnancy. (Chapter 7.5)
Corpus luteum (KŌR-pus LŪ-tē-um): A temporary endocrine structure in female ovaries that is involved in the production of relatively high levels of progesterone and moderate levels of estrogen and inhibin A. (Chapter 7.5)
Cryotherapy (krī-ō-THĔR-ă-pē): A treatment method using extreme cold to destroy abnormal tissue. (Chapter 7.6)
Cystocele (SĬS-tō-sēl): A prolapse of the bladder into the vagina, often referred to as an anterior vaginal prolapse. (Chapter 7.6)
Diagnostic mammogram (dī-ăg-nŏs-tĭk mă-mō-grăm): An enhanced mammogram used when an area of the breast looks abnormal on a screening mammogram. (Chapter 7.6)
Dilation & Curettage (dī-LĀ-shŏn and kūr-ĕ-täj) (D&C): A surgical procedure to remove tissue from the inside of the uterus. (Chapter 7.7)
Dysfunctional uterine bleeding (dĭs-fŭnk-shŭn-ăl yŪ-tĕr-ĭn blēd-ing): Abnormal bleeding from the uterus, often due to hormonal imbalances. (Chapter 7.6)
Dysmenorrhea (dĭs-mĕn-ŏ-RĒ-ă): Painful menstruation, often with cramps. (Chapter 7.5, Chapter 7.6)
Dysparenuria (dĭs-păr-ĕn-ŪR-ē-ă): Pain during sexual intercourse. (Chapter 7.5, Chapter 7.6)
Ectopic pregnancy (ĕk-TŌP-ĭk PRĔG-năn-sē): A pregnancy where the embryo implants outside the uterus, typically in a fallopian tube. (Chapter 7.6)
Embryo (Ĕm-brē-ō): The early developmental stage of an organism following fertilization. (Chapter 7.5)
Endometrial ablation (en-dō-MĒ-trē-ăl ă-BLĀ-shŏn): A procedure that destroys the lining of the uterus to reduce or stop heavy menstrual bleeding. (Chapter 7.6)
Endometrial cancer (en-dō-MĒ-trē-ăl KAN-sĕr): Cancer that originates in the lining of the uterus (endometrium). (Chapter 7.6)
Endometrial sampling (ĕn-dō-MĒ-trē-ăl săm-plĭng): A procedure to remove tissue from the endometrium for examination under a microscope. (Chapter 7.6)
Endometriosis (en-dō-mē-trē-Ō-sĭs): A painful condition where tissue similar to the lining of the uterus grows outside the uterus. (Chapter 7.6)
Endometrium (en-dō-MĒ-trē-um): The innermost lining of the uterus, providing the site for implantation of a fertilized egg or shedding during menstruation. (Chapter 7.4)
Estrogen (ĔS-trŏ-jen): A hormone produced by the ovaries, playing a key role in the female reproductive system, including the menstrual cycle and pregnancy. (Chapter 7.5)
Fallopian tubes (fă-LŌP-ē-an): Tubes that transport oocytes from the ovary to the uterus. (Chapter 7.4)
Fibrocystic breasts (fī-brō-SĬS-tĭk brests): Condition characterized by lumpy or ropelike breast tissue, often experiencing pain, tenderness, and lumpiness especially before menstruation. (Chapter 7.4)
Fimbriae (FĬM-brē-ā): The fringe-like projections at the end of the fallopian tubes, near the ovaries, which help to guide the ovum into the tube after ovulation. (Chapter 7.4, Chapter 7.5)
Fistula (FIS-chŭ-lă): An abnormal passageway between two organs or between an internal organ and the body surface. In the context of the female reproductive system, it could be between the vagina and another organ such as the urinary bladder, colon, or rectum. (Chapter 7.5)
Follicles (FŎL-ĭ-klz): In the context of the female reproductive system, these are the fluid-filled sacs in the ovaries, each containing an immature ovum (egg). (Chapter 7.5)
Follicle stimulating hormone (FŌL-ĭ-kl stim-YŪ-lā-ting HŌR-mōn) (FSH): A hormone released by the brain that stimulates the growth of ova (eggs) in the ovaries. (Chapter 7.5)
Follicular phase (Fŏl-ĭk-yŭ-lăr fāz): The menstrual cycle phase where the endometrium thickens, and follicle growth is stimulated by FSH and LH. (Chapter 7.5)
Gynecologist (gīn-ĕ-KOL-ŏ-jĭst): A physician who specializes in the diagnosis and treatment of disorders of the female reproductive system and the breasts. (Chapter 7.7)
Gynecology (gī-nĕ-KOL-ŏ-jē): Study of the female reproductive system. (Chapter 7.7)
High-grade squamous intraepithelial lesions (hī-grād SKWĀ-mŭs ĭn-tră-ĕ-pĭ-THĒ-lē-ăl LĒ-zhŭns) (HSIL): More serious changes in the cervical cells that indicate a higher risk of progressing to cervical cancer. (Chapter 7.6)
Hirsutism (HĬR-sū-tĭz-ŭm): Excessive hair growth on the face and body, often a symptom of PCOS. (Chapter 7.6)
Hormonal therapy (hôr-MŌ-năl THĔR-ă-pē): Treatment using hormones to block cancer cells from getting the hormones they need to grow. (Chapter 7.6)
HPV test (H-P-V tĕst): A test to check for infection with high-risk types of human papillomavirus that can lead to cervical cancer. (Chapter 7.6)
Human papillomavirus (HYŪ-măn pă-pĭ-lō-mă VĪ-rŭs) (HPV): A group of viruses, some of which can cause genital warts and are associated with an increased risk of cervical and other types of cancers. (Chapter 7.6)
Hysterectomy (his-tĕ-REK-tŏ-mē): Surgical removal of the uterus, which may include the cervix, ovaries, fallopian tubes, and other surrounding structures. (Chapter 7.6, Chapter 7.7)
Hysterosalpingogram (hĭs-tĕ-RO-săl-pĭnj-ō-gram): A common imaging procedure performed to assess for potential causes of infertility in women. During the procedure, radiopaque dye is injected into the uterus and fills the uterine cavity, continues into the fallopian tubes, and eventually reaches fimbriated ends next to the ovaries. Structures are visualized with an x-ray. (Chapter 7.7)
Hysteroscopy (his-tĕ-ROS-kŏ-pē): A procedure to look inside the uterus using a thin, telescope-like device inserted through the vagina and cervix. (Chapter 7.7)
Implantation (ĭm-plan-TĀ-shŏn): The process by which a fertilized egg attaches to the lining of the uterus (endometrium) to begin pregnancy. (Chapter 7.5)
Infertility (ĭn-fĕr-TĬL-ĭ-tē): The inability to conceive after a year or more of regular sexual activity without contraception. (Chapter 7.5)
Intrauterine devices (ĬN-tră-yŪ-tĕr-ēn dī-VĪS-ĭz): Contraceptive devices inserted into the uterus to prevent pregnancy. (Chapter 7.6)
Irregular bleeding (ĭ-rĕg-yŭ-lăr blēd-ing): Bleeding between menstrual periods or after menopause. (Chapter 7.6)
Labia majora (LĀ-bē-uh MĀ-jŏr-uh): Larger outer folds of hair-covered skin that begin just posterior to the mons pubis. (Chapter 7.4)
Labia minora (LĀ-bē-uh mĭ-NŌR-uh): Thinner, hairless, and more pigmented folds found medially to the labia majora, protecting the female urethra and the entrance to the female reproductive tract. (Chapter 7.4)
Lactation (lak-TĀ-shŏn): The process of producing milk in the mammary glands to feed an infant. (Chapter 7.4)
Lactiferous (lak-TĬF-ĕr-us) ducts: Tubes carrying milk from the mammary glands (lobules) to the nipple. (Chapter 7.4)
Laparoscopy (lăp-ă-RŎS-kŏ-pē): A surgical procedure using a laparoscope to examine the organs inside the abdomen. (Chapter 7.6)
Laparotomy (lap-uh-ROT-uh-mee): A surgical procedure with a large incision in the abdomen to access the abdominal organs. (Chapter 7.6)
Laser therapy (LĀ-zĕr THĔR-ă-pē): The use of an intense light beam (laser) to treat various medical conditions, including removing abnormal cervical tissue. (Chapter 7.6)
Loop electrosurgical excision procedure (lōōp ĕ-lĕk-trō-SŬR-jĭ-kăl ĕk-SĬZ-shŭn prō-SĒ-jŭr) (LEEP): A surgical technique used to remove abnormal cervical tissue using a thin wire loop that carries an electric current. (Chapter 7.6)
Low-grade squamous intraepithelial lesions (lō-grād SKWĀ-mŭs ĭn-tră-ĕ-pĭ-THĒ-lē-ăl LĒ-zhŭns) (LSIL): Changes in the cervical cells that are often associated with HPV infection and are typically mild, often resolving on their own. (Chapter 7.6)
Luteinizing hormone (LŪ-tē-ĭ-nīz-ĭng HŌR-mōn) (LH): A hormone involved in triggering ovulation and the development of the corpus luteum. (Chapter 7.5)
Lymphadenectomy (lĭmf-ăd-ĕ-NEK-tŏ-mē): Another term for lymph node dissection, often used in the context of cancer treatment. (Chapter 7.6)
Lymph node dissection (lĭmf nōd dĭ-sĕk-shŏn): Surgical removal of lymph nodes to examine for the presence of cancer. (Chapter 7.6)
Mammogram (MĂM-ō-grăm): An X-ray image of the breast used to detect and diagnose breast abnormalities. (Chapter 7.6, Chapter 7.7)
Mastitis (mas-TĪT-ĭs): Inflammation of the breast, often occurring during lactation. (Chapter 7.5)
Medical oncologists (mĕd-ĭ-kăl ŏn-KOL-ŏ-jĭsts): Physicians specializing in treating cancer with medication. (Chapter 7.6)
Menarche (mĕn-ĂR-kē): The first occurrence of menstruation in a female. (Chapter 7.5)
Menometrorrhagia (mĕn-ō-mĕt-rō-RĀ-jē-ă): Excessive and prolonged uterine bleeding occurring at irregular and/or frequent intervals. (Chapter 7.5)
Menopause (MEN-ŏ-poz): The end of menstrual cycles in a woman’s life, marking the end of reproductive years. (Chapter 7.6)
Menorrhagia (mĕn-ō-RĀ-jē-ă): Excessive menstrual bleeding. (Chapter 7.5, Chapter 7.6)
Menstruation (men-strŪ-Ā-shŏn): The monthly shedding of the endometrial lining in females, typically involving vaginal bleeding. (Chapter 7.5)
Metastasized (mĕ-tăs-tă-sīzd): The process by which cancer spreads from the primary site to other parts of the body. (Chapter 7.6)
Metrorrhagia (mē-trō-RĀ-jă): Bleeding from the uterus at any time other than normal menstruation. (Chapter 7.5)
Modified radical mastectomy (mŏd-ĭ-fīd răd-ĭ-kăl mas-TEK-tŏ-mē): Surgery removing the entire breast with cancer, most of the lymph nodes, and sometimes other tissues. (Chapter 7.6)
Mons pubis (MŎNZ PYŪ-bĭs): A rounded mass of fatty tissue lying over the joint of the pubic bones, becoming covered in hair after puberty. (Chapter 7.4)
Myolysis (mī-OL-ŏ-sĭs): A procedure involving the destruction of fibroids using electric current or freezing. (Chapter 7.6)
Myomectomy (mī-ō-MĔK-tŏ-mē): Surgical removal of fibroids from the uterus. (Chapter 7.6)
Obstetrics (ŏb-STĔT-rĭks) (OB): The branch of medicine and surgery concerned with childbirth and the care of women giving birth. (Chapter 7.7)
Oligomenorrhea (ŏl-ĭ-gō-mĕn-ō-RĒ-ă): Infrequent or very light menstruation. (Chapter 7.5)
Omentectomy (ō-mĕn-TEK-tŏ-mē): Surgical removal of the omentum, a part of the peritoneum in the abdomen. (Chapter 7.6)
Oophorectomy (ō-ŏ-fŏ-REK-tŏ-mē): Surgical removal of one or both ovaries. (Chapter 7.7)
Ovarian cancer (ō-VAR-ē-ăn KAN-sĕr): Cancer that originates in the ovarian tissues. (Chapter 7.6)
Ovarian cyst (ō-VĀR-ē-an sĭst): A fluid-filled sac in the ovary, often part of the normal menstrual cycle or a benign condition. (Chapter 7.6)
Ovary (Ō-văr-ē): Female reproductive gland responsible for producing oocytes (eggs) and hormones. (Chapter 7.4)
Ovulation (ov-yŭ-LĀ-shŏn): The release of an ovum (egg) from the dominant follicle in the ovary, typically occurring around the middle of the menstrual cycle. (Chapter 7.5)
Ovum (Ō-vum): The female reproductive cell, or egg, which, when fertilized by a sperm, can develop into an embryo. (Chapter 7.5)
Papanicolaou smear (păp-ă-NĒ-kă-low smēr) (Pap smear): A screening procedure for cervical cancer and precancerous conditions, involving the collection of cells from the cervix. (Chapter 7.6, Chapter 7.7)
Pelvic inflammatory disease (PĔL-vĭk ĭn-flă-MĂ-tŏ-rē) (PID): An infection of the female reproductive organs, often caused by sexually transmitted infections. (Chapter 7.6)
Perineum (pĕr-ĭ-NĒ-um): The area between the vaginal opening and the anus. (Chapter 7.4)
Peritoneum (pĕr-ĭ-tō-NĒ-ŭm): The membrane lining the abdominal cavity and covering most of the abdominal organs. (Chapter 7.6)
Polycystic ovary syndrome (pŏl-ē-SĬS-tĭk Ō-vă-rē SĬN-drōm) (PCOS): A hormonal disorder causing enlarged ovaries with small cysts on the outer edges. (Chapter 7.6)
Polymenorrhea (pŏl-ē-mĕn-ō-RĒ-ă): Condition characterized by frequent menstrual cycles, shorter than 21 days in length. (Chapter 7.5)
Premenstrual dysphoric disorder (prē-MĔN-strŭ-ăl dis-FŌR-ĭk) (PMDD): A severe form of PMS characterized by significant mood disturbances. (Chapter 7.6)
Premenstrual syndrome (prē-MĔN-strŭ-ăl SĬN-drōm) (PMS): A group of symptoms that occur in women, typically between ovulation and a period. (Chapter 7.6)
Progesterone (pro-JĔS-tĕr-ōn): A hormone released by the corpus luteum in the ovary. It plays a role in the menstrual cycle and in maintaining the early stages of pregnancy. (Chapter 7.5)
Prolapse (PRŌ-laps): The slipping down or displacement of an organ or part, such as the uterus. (Chapter 7.6)
Radiation oncologists (rā-dē-Ā-shŏn ŏn-KOL-ŏ-jĭsts): Doctors who treat cancer using radiation therapy. (Chapter 7.6)
Radiation therapy (rā-dē-Ā-shŏn THĔR-ă-pē): The use of high-energy rays to kill or damage cancer cells. (Chapter 7.6)
Radical hysterectomy (răd-ĭ-kăl his-tĕ-REK-tŏ-mē): Extensive surgery to remove the uterus, cervix, part of the vagina, and sometimes other tissues for cancer treatment. (Chapter 7.7)
Rectocele (RĔK-tō-sēl): A posterior vaginal prolapse where the rectum protrudes into the vagina. (Chapter 7.6)
Salpingectomy (sal-pĭn-JEK-tŏ-mē): Surgical removal of one or both Fallopian tubes. (Chapter 7.7)
Salpingo-oophorectomy (săl-pĭng-gō-ō-ŏf-ō-REK-tŏ-mē): Removal of a Fallopian tube and its corresponding ovary.  (Chapter 7.5)
Speculum (SPEK-yŭ-lŭm): An instrument used to widen the opening of the vagina during medical examinations. (Chapter 7.6, Chapter 7.7)
Subtotal hysterectomy (sŭb-tō-tăl his-tĕ-REK-tŏ-mē): Removal of part of the uterus, leaving the cervix in place. (Chapter 7.7)
Surgeons (SŬR-jŏns): Medical doctors who perform operations. (Chapter 7.6)
Surgery (SŬR-jĕr-ē): Medical procedures involving the manual and instrumental techniques to treat diseases, injuries, or deformities. (Chapter 7.6)
Tampon (TĂM-pon): A plug of soft material inserted into the vagina to absorb menstrual blood. (Chapter 7.6)
Targeted therapy (TĂR-gĭ-tĕd THĔR-ă-pē): Treatment that uses drugs to target specific molecules involved in cancer growth and progression. (Chapter 7.6)
Total abdominal hysterectomy (tō-tăl ăb-DŎM-ĭ-năl his-tĕ-REK-tŏ-mē): Removal of the uterus through an incision in the abdomen. (Chapter 7.7)
Total hysterectomy (tō-tăl his-tĕ-REK-tŏ-mē): Removal of the entire uterus, including the cervix. (Chapter 7.7)
Total hysterectomy/bilateral salpingectomy oophorectomy (tō-tăl his-tĕ-REK-tŏ-mē / bī-LĂT-ĕr-ăl săl-pĭn-JEK-tŏ-mē ō-ŏ-fŏ-REK-tŏ-mē) (TAH/BSO): A surgical procedure involving the removal of the uterus (hysterectomy), both Fallopian tubes (salpingectomy), and both ovaries (oophorectomy). (Chapter 7.7)
Total laparoscopic hysterectomy (tō-tăl lăp-ăr-ŏ-SKŌP-ĭk his-tĕ-REK-tŏ-mē): Removal of the uterus using laparoscopic techniques, involving small incisions and a camera. (Chapter 7.7)
Total mastectomy (tō-tăl mas-TEK-tŏ-mē): Surgical removal of the entire breast that has cancer. (Chapter 7.6)
Toxic shock syndrome (TŌK-sĭk SHŌK SĬN-drōm): A rare, life-threatening complication of certain bacterial infections, associated with tampon use. (Chapter 7.6)
Transvaginal ultrasound (trăns-vă-jĭ-năl ŬL-tră-sound): An ultrasound procedure where a probe is inserted. (Chapter 7.7)
Tubal ligation (TOO-băl lī-GĀ-shŏn): A permanent surgical procedure for female sterilization, involving sealing, tying, or cutting the Fallopian tubes. (Chapter 7.5, Chapter 7.7)
Tubo-ovarian abscess (TŪ-bō ō-VAR-ē-ăn ăb-sĕs): An inflammatory mass involving the fallopian tube and ovary, often a complication of PID. (Chapter 7.6)
Uterine artery embolization (ŪT-ĕ-rīn ăr-tĕr-ē ĕm-bō-lĭ-ZĀ-shŏn): Another term for uterine fibroid embolization. (Chapter 7.6)
Uterine fibroid (ŪT-ĕ-rīn FĪ-brŏyd): Benign tumors in the muscular wall of the uterus. (Chapter 7.6)
Uterine fibroid embolization (ŪT-ĕ-rīn FĪ-brŏyd ĕm-bō-lĭ-ZĀ-shŏn): A procedure to block blood flow to fibroids, causing them to shrink. (Chapter 7.6)
Uterine prolapse (ŪT-ĕ-rīn PRŌ-laps): A condition where the uterus sags or slips from its normal position into the vaginal canal. (Chapter 7.6)
Uterus (YŪ-tĕr-us): A muscular, pear-shaped organ responsible for housing and nourishing a developing fetus. (Chapter 7.4)
Vagina (vă-JĪN-uh): A muscular canal serving as the entrance to the reproductive tract and the exit from the uterus during menstruation and childbirth. (Chapter 7.4)
Vaginal candidiasis (vă-jĭ-năl kăn-dĭ-DĪ-ă-sĭs): A fungal infection in the vagina, commonly known as a yeast infection, causing itching and a thick, white discharge. (Chapter 7.6)
Vaginal hysterectomy (vă-jĭ-năl his-tĕ-REK-tŏ-mē): Removal of the uterus through the vagina. (Chapter 7.7)
Vaginal prolapse (vă-jĭ-năl PRŌ-laps): A condition where the vagina itself sags or slips out of its normal position. (Chapter 7.6)
Vulva (VŬL-vă): The external part of the female genitalia, which includes the labia majora, labia minora, clitoris, and the opening of the vagina. (Chapter 7.4)


7.1: Key Assessment
Overview/Purpose : To review the concepts of Business Law.
Connected Course Competencies and Program Outcomes:
- Describe the sources that establish American law.
- Compare types of corporations.
- Analyze sources of criminal & civil exposure in business.
- Relate the principles of contract law and how they apply to businesses.
- Examine laws pertaining to unfair trade practices.
- Compare insurance for individuals and businesses.
- Distinguish laws covering bankruptcy.
- Explain the theory, practice, and law of disputes and resolution.
- Control Business Processes.
Directions/Task:
To complete this assignment you should complete the following tasks/actions in order.
- Read each question and provide your answers in the spaces provided in the ATTACHED DOCUMENT


2.4: Computing Inverses
View Computing Inverses on YouTube
Calculating the reduced row echelon form of an \(n\)-by-\(n\) invertible matrix \(\text{A}\) can be used to compute the inverse matrix \(\text{A}^{−1}\).
For example, recall how we found the general inverse of a two-by-two matrix by writing \(\text{AA}^{−1} = \text{I}\), that is,
\[\left(\begin{array}{cc}a&b\\c&d\end{array}\right)\left(\begin{array}{cc}x_1&x_2\\y_1&y_2\end{array}\right)=\left(\begin{array}{cc}1&0\\0&1\end{array}\right).\nonumber \]
This single matrix equation is equivalent to two sets of two equations and two unknowns, namely
\[\left(\begin{array}{cc}a&b\\c&d\end{array}\right)\left(\begin{array}{c}x_1\\y_1\end{array}\right)=\left(\begin{array}{c}1\\0\end{array}\right),\quad\left(\begin{array}{cc}a&b\\c&d\end{array}\right)\left(\begin{array}{c}x_2\\y_2\end{array}\right)=\left(\begin{array}{c}0\\1\end{array}\right).\nonumber \]
We can solve these two equations by bringing \(\text{A}\) to reduced row echelon form. There is no point in doing this twice, so instead we form a doubly augmented matrix and go to work on that:
\[\begin{array}{l}\left(\begin{array}{cccc}a&b&1&0\\c&d&0&1\end{array}\right)\to\left(\begin{array}{cccc}1&b/a&1/a&0\\c&d&0&1\end{array}\right)\to\left(\begin{array}{cccc}1&b/a&1/a&0\\0&\frac{ad-bc}{a}&-c/a&1\end{array}\right)\to \\ \left(\begin{array}{cccc}1&b/a&1/a&0\\0&1&-\frac{c}{ad-bc}&\frac{a}{ad-bc}\end{array}\right)\to\left(\begin{array}{cccc}1&0&\frac{d}{ad-bc}&-\frac{b}{ad-bc} \\ 0&1&-\frac{c}{ad-bc}&\frac{a}{ad-bc}\end{array}\right).\end{array}\nonumber \]
The third column of the reduced matrix corresponds to the first column of the inverse matrix, and the fourth column of the reduced matrix correponds to the second column of the inverse matrix. Therefore, we have rederived
\[\text{A}^{-1}=\frac{1}{ad-bc}\left(\begin{array}{rr}d&-b\\-c&a\end{array}\right).\nonumber \]
In other words, by moving \(\text{A}\) to reduced row echelon form while simultaneously performing the same operations on the identity matrix \(\text{I}\), we achieve the following transformation:
\[\left(\begin{array}{cc}\text{A}&\text{I}\end{array}\right)\to\left(\begin{array}{cc}\text{I}&\text{A}^{-1}\end{array}\right).\nonumber \]
To illustrate this algorithm further, we find the inverse of the three-by-three matrix used in our first example. We have
\[\begin{array}{l}\left(\begin{array}{rrrrrr}-3&2&-1&1&0&0\\6&-6&7&0&1&0\\3&-4&4&0&0&1\end{array}\right)\to\left(\begin{array}{rrrrrr}-3&2&-1&1&0&0\\0&-2&5&2&1&0\\0&-2&3&1&0&1\end{array}\right)\to \\ \left(\begin{array}{rrrrrr}-3&2&-1&1&0&0\\0&-2&5&2&1&0\\0&0&-2&-1&-1&1\end{array}\right)\to\left(\begin{array}{rrrrrr}-3&0&4&3&1&0\\0&-2&5&2&1&0\\0&0&-2&-1&-1&1\end{array}\right)\to \\ \left(\begin{array}{rrrrrr}-3&0&0&1&-1&2\\0&-2&0&-1/2&-3/2&5/2\\0&0&-2&-1&-1&1\end{array}\right)\to\left(\begin{array}{rrrrrr}1&0&0&-1/3&1/3&-2/3 \\ 0&1&0&1/4&3/4&-5/4 \\ 0&0&1&1/2&1/2&-1/2\end{array}\right)\end{array}\nonumber \]
and one can check that
\[\left(\begin{array}{rrr}-3&2&-1\\6&-6&7\\3&-4&4\end{array}\right)\left(\begin{array}{rrr}-1/3&1/3&-2/3 \\ 1/4&3/4&-5/4 \\ 1/2&1/2&-1/2\end{array}\right)=\left(\begin{array}{ccc}1&0&0\\0&1&0\\0&0&1\end{array}\right).\nonumber \]
It is also interesting to check that the solution to the equation \(\text{Ax} = \text{b}\) is \(\text{x} = \text{A}^{−1}\text{b}\). Using the \(\text{b}\) from our first example, we have
\[\text{x}=\left(\begin{array}{rrr}-1/3&1/3&-2/3 \\ 1/4&3/4&-5/4 \\ 1/2&1/2&-1/2\end{array}\right)\left(\begin{array}{r}-1\\-7\\-6\end{array}\right)=\left(\begin{array}{r}2\\2\\-1\end{array}\right),\nonumber \]
as obtained previously.


12.7: Reading- Define Retailing
Introduction
Retailing involves all activities required to market consumer goods and services to ultimate consumers who are purchasing for individual or family needs.
By definition, B2B purchases are not included in the retail channel since they are not made for individual or family needs. In practice this can be confusing because many retail outlets do serve both consumers and business customers—like Home Depot, which has a Pro Xtra program for selling directly to builders and contractors. Generally, retailers that have a significant B2B or wholesale business report these numbers separately in their financial statements, acknowledging that they are separate lines of business within the same company. Those with a pure retail emphasis do not seek to exclude business purchasers. They simply focus their offering to appeal to individual consumers, knowing that some businesses may also choose to purchase from them.
We typically think of a store when we think of a retail sale, even though retail sales occur in other places and settings. For instance, they can be made by a Pampered Chef salesperson in someone’s home. Retail sales also happen online, through catalogs, by automatic vending machines, and in hotels and restaurants. Nonetheless, despite tremendous growth in both nontraditional retail outlets and online sales, most retail sales still take place in brick-and-mortar stores.
The Retail Industry
The retail industry covers an enormous range of consumer needs. In reporting on common trends across the major retail segments, the National Retail Federation covers sixteen different categories. As shown below, these categories are not necessarily store types, but they show the breadth of products offered through the retail chain. [1]
| Category | Sample Retailers |
|---|---|
| Auto Aftermarket | Advance Auto Parts, AutoZone, Pep Boys |
| Department Stores | Kohl’s, Macy’s, Nordstrom, Saks Fifth Avenue |
| Drug Stores | CVS, Rite Aid, Walgreen’s |
| Entertainment and Consumer Electronics | AT&T, Apple, Barnes & Noble, BestBuy, GameStop, Toys R Us |
| Footwear | DSW, Foot Locker |
| General Apparel | Forever 21, Gap, H&M, Old Navy, TJ Maxx, Urban Outfitters |
| Health and Beauty | Bath and Body Works, Sally Beauty, Sephora, Ulta |
| Hobby and Craft | Michael’s, Guitar Center, Jo-Ann Fabrics |
| Home Improvement and Hardware | Home Depot, Ikea, Pier 1 Imports, True Value, Williams-Sonoma |
| Jewelry and Accessories | Charming Charlie’s, Coach, Piercing Pagoda, Signet, Tiffany & Co. |
| Mass Merchants | Amazon, Costco, Target, Walmart |
| Restaurants | Chipotle, KFC, McDonald’s, Olive Garden, Starbucks |
| Small-Format Value | Big Lots, Dollar General, Dollar Tree, Family Dollar |
| Sporting Goods and Outdoor | Bass Pro Shops, Cabela’s, Dick’s, Sports Authority, REI |
| Supermarkets | Albertson’s, Kroger, QFC, Safeway, Publix, Whole Foods |
| Women’s Apparel | Ann Taylor, Lane Bryant, Talbot’s, Victoria’s Secret |
The retail industry is designed to create contact efficiency—allowing shoppers to buy what they want efficiently with a smaller number of transactions. This design doesn’t come from a master retail plan. It’s driven by market forces. When a retailer sees an opportunity to expand its offering to increase purchases from customers in one location, it will expand its offering to meet the opportunity. When Barnes & Noble adds Starbucks coffee shops to its locations, customers visit more frequently and stay longer, increasing the chance of additional purchases. Costco recognized that busy holiday shoppers would rather buy a Christmas tree as part of a larger convenience purchase than have a focused (and less convenient) buying experience at a Christmas tree lot. Such opportunities cause retailers to expand their offerings, creating greater contact efficiency for consumers.
Given this logic and opportunity, why doesn’t every retailer become a Walmart Super Store filled with every possible product? Like all organizations that market effectively, retailers shape their offerings to a target buyer. Retailers must also consider the particular shopping experience a buyer is seeking in that moment or context. One experience isn’t right for everyone at the same time; nor are all “experiences” compatible. For example, a buyer is expecting a different buying experience when she fills her car’s gas tank and when she stays at a luxury resort.
Retailers define their target buyer segments, identify the service outputs that those segments require, and match their offerings to provide value to each target segment.
- nrf.com/news/power-players-2015 ↵
Contributors and Attributions
- The Retail Industry. Provided by : Lumen Learning. License : CC BY: Attribution
- Revision and adaptation. Provided by : Lumen Learning. License : CC BY: Attribution
- Chapter 10, Channel Concepts: Distributing the Product, from Introducing Marketing. Authored by : John Burnett. Located at : http://solr.bccampus.ca:8001/bcc/file/ddbe3343-9796-4801-a0cb-7af7b02e3191/1/Core%20Concepts%20of%20Marketing.pdf . License : CC BY: Attribution
- Powell's Books. Authored by : Thomas Hawk. Located at : https://www.flickr.com/photos/thomashawk/2987249389/ . License : CC BY-NC: Attribution-NonCommercial