6.1: Why It Matters- Earth’s Interior
Describe the Earth including the characteristics of the various layers; learn the implications of the different layers.
Introduction
Geologists cannot see directly into the interior of the Earth. They have to rely on various techniques and methods to infer the appearance and physical characteristics of earth’s interior. In this section, we will see how the Earth is structured, what the physical characteristics are, and just how this impacts us living on the Earth.
The Earth’s interior is the basis for geology. If you recall from the Plate Tectonics section, earth exists as we see it today because of plate tectonics. We also learned how plate tectonics is important in the formation of rock, mountains, volcanoes and earthquakes. Studying the interior of the Earth helps learn about all of these and the processes that helped create the Earth and currently drive plate tectonics.
Please watch this short video and take a trip through the various layers of the Earth down to its core:
Learning Outcomes
- Analyze and compare the properties, material, and layers within the Earth’s geosphere.
- Understand how we know about the Earth’s interior and its magnetism.
Contributors and Attributions
- Authored by : Kimberly Schulte and Lumen Learning. Provided by : Lumen Learning. License : CC BY: Attribution


3.3: What are the educational milestones of the 20th century?
-
- Last updated
- Save as PDF
Veronica Montalvo
INTRODUCTION AND THE GROWTH OF EDUCATION
In the United States, the start of the twentieth century marked a movement towards the inclusion of more people than ever into the educational system. In 1900, close to six percent of teenagers graduated from high school (Thattai, 2001). States attempted to increase that number by making that goal more accessible through the construction of more high schools in both urban and rural localities (Wolfe, 2001). Laws were passed that made school mandatory for children until elementary school; later it became obligatory until the child became sixteen years old (Thattai, 2001). However, a good and equal education was not yet widely available to all Americans. Marginalized groups hovered at the fringes of the educational system. African-Americans received unequal and inferior educations as compared to that of whites, as did other minorities and students with limited-English-proficiency (LEP). Women were discriminated against, as well as the handicapped, in being fully included in the educational system. Major developments in the twentieth-century education system include various rulings and acts that promoted a fair and equal education for Americans that had been neglected and marginalized.
G.I. BILL of 1944
Established in 1944, the G.I. Bill was designed to provide assistance to veterans returning from World War II. Although the educational provisions within the Bill were originally intended as “another form of unemployment relief,” the educational system experienced a drastic change in its perception by Americans (Clark, 1998, p. 173). Prior to the influx of veterans in colleges and universities, a college education was perceived as being a privilege of the wealthy and a mark of high status. The veterans returning from WWII were viewed as everyday men, and to see and hear about them going to college broke down that perception and made the dream of a college education more of a reality for all Americans (Clark, 1998). According to Hess and McGuinn (2002), “Education gained a new prominence after World War II” (p. 76). More students were graduating from high school and going to college after the G.I. Bill passed (Hess and McGuinn, 2002).
Aside from changing the perception of college education and increasing enrollments, the G.I. Bill led to the growth of community colleges and vocational schools (Wolfe, 2001). The 2.2 million veterans utilizing the educational benefits of the G.I. Bill (Bound and Turner, 2002) demanded a curriculum with classes more similar to what they had been exposed to in the military. Practicality was a vital aspect in their desired education, and schools responded by creating vocational programs to suit their needs (Clark, 1998). The G.I. Bill impacted future generations by making college more accessible to the average citizen and by causing the expansion of the college curriculum.
BROWN V. BOARD OF EDUCATION, 1954
In 1954, the Supreme Court ruled that segregation in public schools was unconstitutional in Brown v. Board of Education . The decision marked the beginning of more educational opportunities for African-Americans, but these opportunities were still severely limited. The Supreme Court declared that schools must desegregate, but did not make a deadline or any guidelines as to when it must be complete (Carson, 2004). A decade after the decision, less than 10% of black students were attending an integrated school (Ravitch, 2000). Throughout the ‘60s and ‘70s, the government used funds to force schools to desegregate or risk losing their funding (Carper, 2001), and by 1980, the practice of legal segregation for the most part had ended (Thattai, 2001).
Despite the long delay in achieving the goal of desegregation, the message that Brown delivered impacted the educational system and future policy in civil rights (Carson, 2004). Brown revealed the potential for other minority groups to begin the struggle for equal educational access (Gándara, Moran, and García, 2004). Equal and fair education began to be viewed as “the birthright of a free citizenry” (Hess and McGuinn, 2002, pp. 76–77), and more groups began demanding that right.
ELEMENTARY AND SECONDARY EDUCATION ACT OF 1965
The Elementary and Secondary Education Act of 1965 sought to equalize the education opportunities for all children. As the start of federal government grants to states for education (Hess and McGuinn, 2000), the law attempted “to compensate in some sense for disadvantages due to inequities in the social system” (Wolfe, 2001). President Johnson hoped that increasing and equalizing education for all children would one day rid the country of poverty (Easley, 2005). Funds were provided to the states for services for poor and minority students (Baker, 2001) as well as for “school library resources, textbooks, and other instructional materials for school children” ( Digest of Education Statistics , 2006). In 1967, Title VII authorized grants to be given for programs for LEP students (Baker, 2001). More than giving funds for different programs for the poor and minorities, ESEA along with the Civil Rights Act of 1964 aided in providing funds for the desegregation of southern schools who had refused to do so (Ravitch, 2000), more than a decade after the Brown v. Board of Education ruling. ESEA served to make an equal education more obtainable for all classes and races.
TITLE IX OF 1972
The place of women within the educational system was limited in terms of opportunities and the material being taught. The Civil Rights Movement during the ‘60s and ‘70s led women to protest more and demand equality in education. The Civil Rights Act of 1964 included the requirement that grants be given to the states in order for them to work towards that gender equality in education, and in 1972, Title IX of the Education Amendments was passed (Marshall, 2002). Title IX required that there be gender equality in schools that received money from the government and that “curricula should not stereotype girls’ and boys’ interests and careers” (Marshall, 2002, p. 712). In spite of the worthwhile objectives of Title IX, it was a feeble mandate. No penalties existed for schools that refused to comply, and a way to even supervise them was not set up until a quarter of the century after the passage of Title IX (Marshall, 2002).
In 1974, the Women’s Educational Equity Act (WEEA) was passed. This act provided a financial backbone to Title IX with funds granted to the schools and agencies in order to fulfill the goals of Title IX ( Women’s Educational Equity ). Title IX and WEEA made great strides in opening up more doors to education for women in the twentieth century.
INDIVIDUALS WITH DISABILITIES ACT OF 1975
The place of handicapped children in schools improved in the twentieth century. Almost five percent of students have a mental disability (Gunning, 2008), and with the 1975 Education for All Handicapped Children’s Act, they are able to receive a better education (Keyes, Hanley-Maxwell, and Capper, 1999). The name later changed to the Individuals with Disabilities Act (IDEA), but the goal of guaranteeing an education to disabled students remained the same (Keyes, Hanley-Maxwell, and Capper, 1999). A “free appropriate public education” or FAPE requires that “special education and related services are provided at public expense” (McLaughlin and Thurlow, 2003, p. 436). Disabled children must be placed in the least restrictive environment possible, meaning that their educational environment is as close to that of their nondisabled classmates as possible (Keyes, Hanley-Maxwell, and Capper, 1999). Individualized Education Programs (IEPs) are used to monitor the learning disabled student’s progress, and in 1997, assessments became mandatory for disabled students in order to make the schools more accountable for the students’ progress (McLaughlin and Thurlow, 2003). If necessary, accommodations in the assessments may be used (Gunning, 2008). Thanks to IDEA, more disabled students are graduating than if IDEA had not been passed ( Special Education and the Individuals with Disabilities Education Act ).
CONCLUSION
The twentieth century achieved a great deal in terms of including more groups that had been previously excluded or marginalized. A great deal still remains to be done in making education truly equal and accessible to every American, but the foundation has been laid for more work in the twenty-first century. Each American deserves to have equal educational opportunities, and as society progresses and more policies are created, that goal may be achievable.
Exercise \(\PageIndex{1}\)
1. In 1956, what type of education might most African Americans in the deep south likely have recieved?
a. A separate but equal education to that of whites
b. A better education but still in segregated schools
c. An inferior education compared to that of whites
d. An education that was rapidly improving since 1954
2. After 1975, in what kind of learning environment are handicapped children found?
a. Separate classrooms where they are taught basic skills
b. A school day split between a special education class and a regular class
c. Full integration into regular classrooms with nondisabled students
d. Separate schools that can accommodate their needs more
3. In 1970, women's education most likely included what class?
a. Physics
b. Auto repair
c. Calculus
d. Home economics
4. After World War II, which belief suporrted the passage of the G.I. Bill?
a. Veterans returning home would be mostly unemployed
b. Veterans would be eager to further their education while working
c. There would be a surplus of jobs and veterans could be picky
d. Veterans would probably not use the benefits anyway
5. What type of classes could most likely appeal to the returning World War II Veterans?
a. Art history
b. English composition
c. Mechanics
d. Psychology
- Answer
-
1. B
2. B
3. D
4. A
5. C
References
Baker, B. D. (2001). Living on the edge of state school-funding policies: the plight of at-risk, limited-English-proficient, and gifted children. Educational Policy , 15, 699-723.
Bound, J. and S. Turner. (2002). Going to war and going to college: did World War II and the G.I. Bill increase educational attainment for returning veterans? Journal of Labor Economics , 20:4, 784-815.
Carper, J. C. (2001). The changing landscape of U.S. education. Kappa Delta Pi Record , 37 no3, 106-110.
Carson, C. (2004). Two cheers for Brown v. Board of Education. The Journal of American History , 9:1, n.p.
Clark, D. A. (1998). “The two Joes meet—Joe College, Joe Veteran”: the G.I. Bill, college education, and postwar American culture. History of Education Quarterly ,38 no2, 165-189.
Digest of Educational Statistics: Chapter 4 Federal Programs for Education and Related Activities . 2006. Retrieved February 1, 2008 from Department of Education web site: http://nces.ed.gov/programs/digest/d06/ch_4.asp .
Easley II, J. (2005). The political tension of education as a public good: the voice of a Martin Luther King, Jr., scholar. Education and Urban Society , 37, 490-505.
Gándara, P., R. Moran, E. Garcia. (2004). Legacy of Brown: Lau and language policy in the United States. Review of Research in Education , 28, 27-46.
Gunning, T. G. (2008). Creating literacy instruction for all students (6th ed.). New York City, NY: Pearson Education, Inc.
Hess, F. M. and P. J. McGuinn. (2002). Seeking the mantle of “opportunity”: presidential politics and the educational metaphor, 1964-2000. Educational Policy , 16, 72-95.
Keyes, M. W., C. Hanley-Maxwell, and C. A. Capper. “Sprirituality? It’s the core of my leadership”: empowering leadership in an inclusive elementary school. Educational Administration Quarterly , 35,203-237.
Marshall, C. (2002). Teacher unions and gender equity policy for education. Educational Policy , 16, 707-730.
McLaughlin, M. J. and M. Thurlow. (2003). Educational accountability and students with disabilities: issues and challenges. Educational Policy , 17, 431-451.
Ravitch, D. (2000). Left back: a century of battles over school reform . New York City, NY: Touchstone.
Special Education and the Individuals with Disabilities Education Act . (n.d.). Retrieved February 1, 2008 from National Education Association Web site: www.nea.org/specialed/index.html?mode.
Thattai, D. (2001, November). A history of public education in the United States. Journal of Literacy and Education in Developing Societies ,1:2. Retrieved February 1, 2008 from www.servintfree.net/~aidmn-ejournal/.
Wolfe, M. P. (2001). Reflections on the most important educational developments of the 20th century: Kappa Delta Pi laureates. The Educational Forum , 65 no2, 146-163.
Women’s Educational Equity . (n.d.). Retrieved February 1, 2008 from Department of Education Web site: http://www.ed.gov/pubs/Biennial/125.html .


9.3: Poles
In the previous section, we referred to situations where \(f(z)\) is non-analytic at discrete points. “Discrete”, in this context, means that each point of non-analyticity is surrounded by a finite region over which \(f(z)\) is analytic, isolating it from other points of non-analyticity. Such situations commonly arise from functions of the form \[f(z) \approx \frac{A}{(z-z_0)^n}, \quad \mathrm{where}\;\; n\in\{1,2,3,\dots\}.\] For \(z = z_0\) , the function is non-analytic because its value is singular. Such a function is said to have a pole at \(z_0\) . The integer \(n\) is called the order of the pole.
Residue of a simple pole
Poles of order 1 are called simple poles , and they are of special interest. Near a simple pole, the function has the form \[f(z) \approx \frac{A}{z-z_0}.\] In this case, the complex numerator \(A\) is called the residue of the pole (so-called because it’s what’s left-over if we take away the singular factor corresponding to the pole.) The residue of a function at a point \(z_0\) is commonly denoted \(\mathrm{Res}[f(z_0)]\) . Note that if a function is analytic at \(z_0\) , then \(\mathrm{Res}[f(z_0)] = 0\) .
Example \(\PageIndex{1}\)
Consider the function \[f(z) = \frac{5}{i-3z}.\] To find the pole and residue, divide the numerator and denominator by \(-3\) : \[f(z) = \frac{-5/3}{z-i/3}.\] Thus, there is a simple pole at \(z = i/3\) with residue \(-5/3\) .
Example \(\PageIndex{2}\)
Consider the function \[f(z) = \frac{z}{z^2 + 1}.\] To find the poles and residues, we factorize the denominator: \[f(z) = \frac{z}{(z+i)(z-i)}.\] Hence, there are two simple poles, at \(z = \pm i\) .
To find the residue at \(z = i\) , we separate the divergent part to obtain \[\begin{align} f(z) &= \frac{\left(\frac{z}{z+i}\right)}{z-i} \\ \Rightarrow\quad \mathrm{Res}\big[\,f(z)\,\big]_{z=i} &= \left[\frac{z}{z+i}\right]_{z=i} = 1/2. \end{align}\] Similarly, for the other pole, \[\mathrm{Res}\big[\,f(z)\,\big]_{z=-i} = \left[\frac{z}{z-i}\right]_{z=-i} = 1/2.\]
The residue theorem
In Section 9.1, we used contour parameterization to calculate \[\oint_{\Gamma} \frac{dz}{z} = 2\pi i,\] where \(\Gamma\) is a counter-clockwise circular loop centered on the origin. This holds for any (non-zero) loop radius. By combining this with the results of Section 9.2, we can obtain the residue theorem :
Theorem \(\PageIndex{1}\)
For any analytic function \(f(z)\) with a simple pole at \(z_0\) , \[\oint_{\Gamma[z_0]} dz \; f(z) = \pm 2\pi i \, \mathrm{Res}\big[\,f(z)\,\big]_{z = z_0},\] where \(\Gamma[z_0]\) denotes an infinitesimal loop around \(z_0\) . The \(+\) sign holds for a counter-clockwise loop, and the \(-\) sign for a clockwise loop.
By combining the residue theorem with the results of the last few sections, we arrive at a technique for integrating a function \(f(z)\) over a loop \(\Gamma\) , called the calculus of residues :
-
Identify the poles of
\(f(z)\)
in the domain enclosed by
\(\Gamma\)
.
-
Check that these are all simple poles, and that
\(f(z)\)
has no other non-analytic behaviors (e.g. branch cuts) in the enclosed region.
-
Calculate the residue,
\(\mathrm{Res}[f(z_n)]\)
, at each pole
\(z_n\)
.
-
The value of the loop integral is \[\oint_\Gamma dz\; f(z) = \pm 2\pi i \sum_n \mathrm{Res}\big[\,f(z)\,\big]_{z = z_n}.\]The plus sign holds if
\(\Gamma\)
is counter-clockwise, and the minus sign if it is clockwise.
Example of the calculus of residues
Consider \[f(z) = \frac{1}{z^2 + 1}.\] This can be re-written as \[f(z) = \frac{1}{(z + i)\,(z-i)}.\] By inspection, we can identify two poles: one at \(+i\) , with residue \(1/2i\) , and the other at \(-i\) , with residue \(-1/2i\) . The function is analytic everywhere else.
Suppose we integrate \(f(z)\) around a counter-clockwise contour \(\Gamma_1\) that encloses only the pole at \(+i\) , as indicated by the blue curve in the figure below:
According to the residue theorem, the result is \[\begin{align} \oint_{\Gamma_1}dz \; f(z) &= 2\pi i\, \mathrm{Res}\big[\,f(z)\,\big]_{z = i} \\ &= 2\pi i \cdot \frac{1}{2i} \\& = \pi.\end{align}\] On the other hand, suppose we integrate around a contour \(\Gamma_2\) that encloses both poles, as shown by the purple curve. Then the result is \[\oint_{\Gamma_2}dz \; f(z) = 2\pi i \cdot \left[\frac{1}{2i} - \frac{1}{2i}\right] = 0.\]


Positive conflict comes from recognizing disagreement as part of a healthy process. It is an exchange of passionate ideas. This exchange helps us find creative solutions as well as testing weaknesses of current solutions. The difficulty in keeping conflict positive is in having norms regarding how ideas are expressed and discussed.
12.12: Conflict Resolution
- Describe various ways of interpreting and responding to conflict in interpersonal communication
Interpersonal conflict occurs in the workplace between individuals. Conflict can also occur within working groups and is sometimes magnified in that setting. When we hear the word “conflict,” we typically think about all the negatives associated with the word. Most of us would like to avoid conflict entirely; however, conflict can also be productive.
Conflict is necessary for good results. Learning to understand and manage conflict is critical when working in organizations. Let’s explore conflict more deeply in order to understand its broad impact and its direct impact on workplace communication.
Sources of Team Conflict
Let’s take a look at a few examples of conflict within teams.
A new product team may find itself split between allocating funds for the second release of the device or bringing a new product to market. The team may find about half of its members preferring one path and the other half advocating for the other.
In this case, the team may split into two factions—or more if there is additional disagreement within each group. Even if business considerations support one group’s position more strongly, powerful personalities, interpersonal complexity, and group history can come into play to overwhelm those practical factors.
Employees may think, “Why doesn’t the boss just ask us? We do it every day and that will never work.” The boss may think, “Those employees don’t realize what that will cost. It will blow the entire department budget in half the time.”
Gaps in communication between leaders and the teams they lead can cause particularly thorny conflicts. There may be conflict with management because management has not given clear goals to the team or may not be supporting the team. The organization could have a culture that does not allow teams to work effectively. In extreme situations, this can lead to the team’s refusal to follow the directions of its leader.
A company organizationally separates its sales employees from its service (installation and maintenance) employees. On more than one occasion, Sales asked, “What are those service people thinking? We can’t charge the customer for every little thing.” Equally frequently, service is asking, “What are those sales people thinking? Are they giving the company away? We can’t install it for that little.”
When different teams don’t take the time to understand the roles and tasks of individuals on different teams, conflict can arise between different functional groups within the organization.
Unproductive negative conflict should be avoided and must be swiftly addressed and resolved when it does present itself. Because of the dangerous nature of negative conflict and the toll it takes on productivity and moral, it may potentially lead to Human Resource Management issues or even a lawsuit.
What are the Symptoms of Team Conflict?
Symptoms of conflict are seen in the communications of the members. They illustrate themselves in a variety of ways. Once we recognize the symptom, we can find a solution.
Almost everyone has endured the experience of being part of a team that was plagued with conflict. Whether in a large group that erupts in anger and can’t finish a meeting, or a small group of two or three individuals that resort to backbiting and gossiping to vent frustration over a conflict, everyone has been a part of a team where conflict has gotten out of control. With this in mind, there are several symptoms of conflict that can be identified in groups that can help them to recognize and manage conflict before it tears them apart. By identifying the following symptoms related to communication, trust, and opposing agendas, the team leader can identify conflict before it erupts. As you read through these symptoms, think of the teams that you are a part of and look for symptoms that exist in your team.
One common symptom of conflict is a lack of communication or a lack of respectful communication. This is most often seen when teams fail to have meaningful meetings. Most often, non-communicating meetings are characterized by team members sitting and listening to what the boss has to say. Often chatter or silence prevails among such teams. A lack of communication can also be noted when team members don’t get along and so refuse to talk to each other. These feuds create barriers within teams and prevent communication. A lack of communication or disrespectful communication leads to a lack of trust, which is another symptom of team conflict. Teams that fail to produce desired results often lack the trust in one another as team members that is necessary to succeed. Without trust in a team, verbal or non-verbal conflict becomes the norm of the team. Team members spend more energy protecting their own positions and jobs than they do producing what is required for the team’s success. When trust erodes in a team, the habit of blaming others becomes the norm as individuals try to protect themselves. Team members become enemies that compete against each other rather than allies that build and help one another to achieve a common goal. Teams that lack trust often gossip about other members or have frequent side conversations after meetings to discuss opposing opinions.
Another symptom of team conflict can be seen when team members have opposing agendas. This is not to be confused with members who have different opinions. Having different opinions in a group can be very healthy if managed correctly because it can create better ideas and ways of getting the job done. However, when team members have opposing agendas, more is at stake than differing opinions; two individuals are fiercely committed to the exact opposite approach. Opposing agendas can create confusion in team members and can cause them to lose sight of their role in the team and of the team’s final goal. Teams must work toward a common goal in order to be successful. Extreme effort must be made to reconcile differences, or such a team can look forward to failure.
Avoiding Destructive Conflict
In most instances of team conflict, avoidance is a worse solution than engagement with the conflicting situation. Moreover, avoided conflict will lead to less optimal solutions and may even prevent the team from finishing a project. Thus, from a manager’s perspective, it is a simple equation of a cost/benefits analysis in that the cost to the organization is greater when teams avoid conflict than when they engage in it.
Fostering support, trust, and open communication is also essential if relationship conflicts are to be reduced and quickly resolved. Open communication can be established by the following:
- Establish ground rules. Some rules might include the following: Take turns when talking and do not interrupt. Ensure that each team member has equal time when stating their perspective. Listen for something new and bring something new to the discussion. Avoid restating the facts and “talking in circles.” Avoid power plays, and eliminate status or titles from the discussion.
- Listen actively and compassionately. Avoid thinking of a counterargument while the other person is speaking. Listen to the other person’s perspective rather than listening to your own thoughts. Don’t make an effort to remember points just so you can refute them one by one.
- Point out the advantages of resolving the conflict. “I know you feel that is too much for us to spend right now, but we should figure out how to solve this problem. Then, we can figure out when to spend that money.”
- Maintain a neutral vantage point and be willing to be persuaded. “Can you help me understand why….”
- Avoid all-or-none statements such as “always” and “never,” and point out exceptions when these statements are used. Rather than say, “we have never done it that way,” try “we had good reason for not doing that in the past, but let’s talk this through to see if conditions have changed.”
- Create a goal of discovery rather than of winning or persuading. “Let’s set aside our final decision until our next meeting. This meeting, let’s brainstorm solutions and try to put a cost to each.”
- Be alert to common goals and where goals overlap as each party is communicating their perspective. “I’m not sure I reach the same conclusion as you, but a 5% decrease is something we do all appreciate.”
- Use clarifying statements to ensure the other party feels understood and listened to. “What I heard you say is that you feel unappreciated and that you lack vital feedback to help you perform, is this correct?”
- Help team members to separate the problem from the person. “I know your job is to remind us of the rules, but could we try to approach this a different way?”
- Use techniques such as role-playing, putting oneself in the competitor’s shoes, or conducting war games. Such techniques create fresh perspectives and engage team members. “Let me try to be the devil’s advocate. You tell me your solution, and I’ll be the technician trying to poke holes in the idea.”
- Team members should recognize each other for having expressed their view and feelings. “I’m glad to hear your side all the way through. Thank you.”
- Help each team member to understand all the other perspectives, and help them to re-frame the situation. “So, if I heard you correctly, you are concerned about x. Is it possible that we could address this by trying y?”
Solutions to Conflict
Conflict is a natural and necessary element of a healthy team experience. It will occur even in the best teams. It can be constructive.
A team that never experiences conflict is likely to be less productive than a team that does experience conflict. This is especially true if the task that a team is attempting to complete is complex in nature or highly detailed. Without having members question specific actions, specific decisions, or the specifics of the proposed solution, it may appear to the team that there is only one way to solve the problem or complete the task.
When choosing team members, consider making choices that will promote healthy conflict. You will want to avoid fostering groupthink while avoiding people who already clash with one another. People who want peace at any price and scramble to quash even productive, positive conflict are also not especially useful. While you may choose individuals for their personality traits, commitment is equally important. If team members are individually or collectively indifferent toward the overall goal, they probably will not perform well. A lack of commitment can also lead to a lack of conflict. If the team is committed to the overall goal and members are well chosen, there can be a healthy dose of conflict in the process to complete the task.
When conflict does occur, it is important to address it immediately. Although developing a solution to the conflict may take time, acknowledging it will help to ensure that it can become productive to the team. “Whatever the problem, effective teams identify, raise, and resolve it. If it’s keeping them from reaching their goal, effective teams try to do something about it. They don’t ignore it and hope it goes away.” [1] By not addressing conflict, the leader risks sending the message that conflict is unmanageable, which can cause vested members to become complacent or feel their input is not valued. In the worst-case scenario, a conflict that is not resolved could go from being task oriented to personal.
How Do Teams Prevent Damaging Conflict?
In order to prevent damaging conflict, the team leader must lay a conflict-friendly foundation for the team. The following approach will help the team leader to set the stage for conflict that is creative and productive:
- Set a clear goal for the team.
- Make expectations for team members explicit.
- Assemble a heterogeneous team, including diverse ages, genders, functional backgrounds, and industry experience.
- Meet together as a team regularly and often. Team members who don’t know one another well don’t know each other’s positions on the issues, impairing their ability to argue effectively. Frequent interaction builds the mutual confidence and familiarity team members require to express dissent.
- Assign roles such as devil’s advocate and sky-gazing visionary and change these roles up from meeting to meeting. This is important to ensure all sides of an issue have been considered.
- Use techniques such as role-playing, putting oneself in the competitor’s shoes, or conducting war games. Such techniques create fresh perspectives and engage team members.
- Actively manage conflict. Don’t let the team acquiesce too soon or too easily. Identify and treat apathy early, and don’t confuse a lack of conflict with agreement.
Resolving Conflict
Interpersonal conflict should be managed and resolved before it degenerates into verbal assault and irreparable damage to a team. Dealing with interpersonal conflict can be a difficult and uncomfortable process. Usually, as team members, we use carefully worded statements to avoid friction when confronting conflict.
The first step to resolving interpersonal conflict lies in acknowledging the existence of the interpersonal conflict. Recognizing the conflict allows team members to build common ground by putting the conflict within the context of the larger goal of the team and the organization. Moreover, the larger goal can help by giving team members a motive for resolving the conflict.
As team members, we all understand the inevitability of interpersonal conflicts. Open and supportive communication is vital to a high performing team. One way to achieve this is by separating the problem from the person. Problems can be debated without damaging working relationships. When interpersonal conflict occurs, all sides of the issue should be recognized without finger-pointing or blaming. Above all, when a team member gets yelled at or blamed for something, it has the effect of silencing the whole team. It gives the signal to everyone that dissent is not allowed, and, as we know, dissent is one of the most fertile resources for new ideas.
When faced with conflict, it is natural for team members to become defensive. However defensiveness usually makes it more difficult to resolve a conflict. A conflict-friendly team environment must encourage effective listening. Effective listening includes listening to one another attentively, without interruption (this includes not having side conversations, doodling, or vacant stares). The fundamentals to resolving team conflict include the following elements:
- Prior to stating one’s view, a speaker should seek to understand what others have said. This can be done in a few clarifying sentences.
- Seek to make explicit what the opposing sides have in common. This helps to reinforce what is shared between the disputants.
- Whether or not an agreement is reached, team members should thank each other for having expressed their views and feelings. Thanking the other recognizes the personal risk the individual took in breaking from groupthink and should be viewed as an expression of trust and commitment toward the team.
- LaFasto, Frank M. J., and Carl E. Larson. When Teams Work Best: 6,000 Team Members and Leaders Tell What It Takes to Excel . Thousand Oaks, Calif: Sage Publications, 2002, p. 81.
Contributors and Attributions
- Conflict Resolution. Authored by : Susan Kendall. Provided by : Lumen Learning. License : CC BY: Attribution
- Thinking About Conflict. Authored by : Scott T Paynton and Linda K Hahn. Provided by : Humboldt State University. Located at : https://en.wikibooks.org/wiki/Survey_of_Communication_Study . Project : Survey of Communication Study. License : CC BY-SA: Attribution-ShareAlike
- Managing Groups and Teams/Conflict. Authored by : Wikibooks. Located at : https://en.wikibooks.org/wiki/Managing_Groups_and_Teams/Conflict . License : CC BY-SA: Attribution-ShareAlike


Skip to main content
12.4.2: Patients Who Are Unable to Perform Mouth Hygiene Independently, Such as an Unconscious Patient
-
-
Last updated
-
-
Save as PDF
-
-
Complete hand hygiene and assemble needed equipment.
-
Put the patient in a
side–
lying
position
for safety. Turn their head to the side.
-
Place a towel or waterproof pad under their cheek and chin to prevent the patient or bed linens from getting wet.
-
Place an emesis basin against the side of their mouth and cheek.
-
Place a padded tongue blade on the side of their mouth to keep their mouth open. To make a padded tongue blade, place two wooden tongue blades together. Wrap gauze over the top half and tape it into place.
-
Never put your fingers inside their mouth because the patient may bite down, even if they do not mean to.
-
Brush teeth gently, using a dry toothbrush or with a mouth swab. Dip the swab in solution and squeeze excess solution from the swab. Swab all surfaces of their teeth, gums, inside their cheeks, the roof of their mouth, and tongue. Use clean swabs as necessary.
-
Rinse entire mouth with a clean swab. Ensure there are no pooled secretions. Suction excess secretions as directed in the Care Plan.
-
Ensure the patient’s mouth, face, and neck are dry.
-
Apply moisturizer to lips.
-
Return the patient to a comfortable position. Lower the bed to its lowest height and raise side rails.
-
Put away equipment and supplies.
-
Remove your gloves. Wash and dry your hands.
-
Document completion of task and record any changes in condition or behavior. Report any tooth or mouth conditions observed, such as sores, open areas, or bleeding from gums, tongue, or teeth. Report any new broken or missing teeth.


18.6: Transformational Leadership
-
- Last updated
- Save as PDF
To cope with a changing world any entity must develop the capability of shifting and changing, of developing new skills and attitudes: in short the capability of learning (De Gues, 1997, p. 20).
Transformational leadership provides a useful and relevant perspective from which to examine change processes involved in adoption and use of educational technologies. Research into factors affecting technology use for teaching and learning by Byrom and Bingham (2001) found that leadership was a key ingredient in the adoption and use of educational technologies. Leadership practice started with vision, leading through example, included support for followers, and shared leadership that maintained focus through evaluation of the change implemented. The International Society for Technology in Education (2001), through its National Educational Technology Standards Project, found that the core curriculum and content area skills required for school technology leaders were leadership and vision; learning and teaching; productivity and professional practice; support, management and operations; assessment and evaluation; and social, legal and ethical issues.
These characteristics of leadership are clearly described in the literature on transformational leadership, hence its applicability to understanding change in the context of implementing educational technologies. Substantial research conducted by Burns (1978), Leithwood & Jantzi (2000, 2005) indicates that complex and dynamic change, such as the implementation of educational technologies, is more likely to occur through transformational leadership. Transformational leadership “can be thought of as a set of behaviors of individuals who accomplish change” (Valdez, 2004, para. 12), and “is about change, innovation, and entrepreneurship” (Tichy & Devanna, 1990, p. xii). Transformational leadership is dynamic. It is building motivation and purpose in followers where the greater good of the organization is placed ahead of personal interests. For Burns (2003), “a leader not only speaks to immediate wants, but elevates people by vesting in them a sense of possibility, a belief that changes can be made and that they can make them” (p. 239).
Bennis and Nanus (1985) describe transformational leaders as using knowledge and engendering trust to build commitment through communication to a shared vision to support change and transformation. Transformational leadership is the development of vision within a supportive culture, and the articulation of goals to achieve a collective vision (Silins & Mulford, 2002). Transformational leadership invokes change, and is more about innovativeness than innovation, less about strategy and more about strategizing. It is shared leadership, where everyone involved in the organization are leaders. This requires participation, vision, collaboration, and reflection—all of which require a sense of community and a direct link between leading and learning (Lambert, 2002). Leithwood and Duke (1999) describe seven dimensions of transformational leadership:
- creating a shared vision
- setting goals
- providing intellectual stimulation
- supplying individual support
- modelling effective practice
- meeting high expectations
- developing a positive culture, and creating structures that support active involvement in decision-making.
Developing shared vision and setting goals is a process that engages leaders and followers to achieve something greater than if left to their own self-interests. The process helps to create new structures to support active involvement. Transformational leaders engage process, and then promote change by valuing individual difference and supporting followers. They model the practice they wish others to emulate, and keep true to the vision and goals. They instill feelings of confidence, admiration and commitment in followers. Each follower is coached, advised, and delegated some authority within the organization. The transformational leader stimulates followers intellectually, arousing them to develop new ways to think about problems, and in the case of e-learning, new ways to think about the organization of learning and delivery of instruction.
Leithwood and Jantzi (2005) shaped a set of transformational leadership behaviours (TLBs) derived from their meta-analysis of the literature in school settings (see Table 18.1, Transformational Leadership Behaviours for details). Three of the groups of behaviours— setting directions, helping people, and redesigning the organization—are based on transformational leadership theory, while the last, an aggregate of transactional and managerial leadership, is based on Bass’s (1985) transactional model and attempts to fill gaps in transformational leadership theory. In setting directions, transformational leaders identify and articulate a vision, foster acceptance of group goals, and ensure high performance expectations. The vision may be one that is developed in a community collectively, or one that the leader espouses and articulates to followers for their endorsement and engagement.
In helping people, transformational leaders motivate by modelling high expectations, or “idealized influence” as described by Bass (1985), and they encourage and support followers to do the same. Knowing your followers is key to this dimension. In the case of adoption of educational technologies, leaders embrace and use technology as part of their professional work, and encourage followers to do the same for their own professional needs as well as part of their professional practice with learners. Transformational leaders create formal structures for dialogue and discussion that build collaboration, and expand those structures to include opportunities to engage all constituents.
Transformational leadership, then, is a model that describes how to build capacity for change that can support implementation of an e-learning program. Previous models of leadership stressed centralized control within hierarchical organizational structures, leading to a “top down” approach. A decentralized model based on flatter organizational structures leads to a “bottom up” approach associated with a transformational model of leadership (see Bass, 1985, 1997; Silins & Mulford, 2002; Leithwood, 2005). For example, in a three year study of high schools in two Australia states, Silins & Mulford (2002) found that transformational leaders demonstrated active interest in teaching and learning, but more importantly they “help establish the systems and structures that support ‘bottom up’ approaches and allow ‘top down’ approaches to succeed [and] are effective because they are, above all, people-centred” (p. 31).
Transformational leaders focus on those involved in the change, their relationships, and seek to transform feelings, attitudes and beliefs in support of organizational direction, established through a clear, shared vision. In his meta-analysis of the research on transformational leadership, Leithwood (2005) concluded that “as an image of ideal practice, transformational leadership currently is challenged only by instructional leadership in both practitioner and scholarly communities” (p. 2). Leithwood cautions, however, that most research on transformational leadership in non-school contexts has been restricted to the work of Bass (1985), while he and his colleagues have done the majority of the research in school contexts.
Theory is one thing, practice yet another. Transformational leadership theory is relatively new. While more research will substantiate its usefulness, particularly as it applies to adoption and use of educational technologies, it has limitations. While the literature describes how vision, goal orientation, and progress is communicated, it does not describe how that communication is received. Too often superficial dialogue is created when transformational leadership processes are used, and while communication occurs, understanding does not. Transformational leadership theory also claims to explore equality and justice issues, yet studies reflect organizational change, not issues of equity, social justice— the “digital divide” for any e-learning program. Further research into the effects on pedagogy of the adoption of educational technologies, particularly with a view to equity issues in e-learning programs, is worth consideration.


9.3: Gender Disparities
By the end of this section, you should be able to:
- Describe how gender affects health outcomes.
- Assess influencing factors contributing to gender disparities.
- Discuss health disparities faced by the LGBTQIA+ community.
Research shows men and women experience different health outcomes beyond what would be expected for sex-specific conditions and treatments. Women and members of the LGBTQIA+ community frequently experience poorer health outcomes and face more barriers to health care access.
Concepts Related to Sex and Gender
The terms sex and gender are sometimes used interchangeably. While they are interrelated terms, they have distinct differences. Sex refers to the physiological and biological characteristics of males and females. Gender refers to male and female characteristics that are socially constructed (World Health Organization [WHO], 2023). Gender identity refers to a person’s internal experience and belief of gender, which may or may not correspond to their physiology or designated sex at birth (WHO, 2023). LGBTQIA+ is used to refer collectively to lesbian , gay , bisexual , transgender , queer/questioning , intersex, asexual/aromantic/agender, and other related groups. The terms used to describe these groups are fluid and may change frequently, and not all people feel that they are represented by a specific term.
Physical differences can result in the development of sex-specific conditions . For example, each sex has a different reproductive system and corresponding reproductive diseases. Gender health disparities appear to encompass both sex and gender characteristics as biological, psychological, and social mechanisms intertwine to affect health outcomes in those with long-term disabling conditions (Thakral et al., 2019).
In this video, women share their experiences of health care bias that delayed their diagnoses and treatments.
Watch the video, and then respond to the following questions.
- What are the trends or consistencies in the cases described in this video?
- What can nurses learn from these stories that they can incorporate into their practice?
Gender Differences
Gender norms are social and cultural principles that influence ideas on how different genders are supposed to behave in society. Such norms are often harmful. For example, gender stereotypes , or generalized preconceptions about what roles or traits should be performed by men and women, often limit their potential and create inequality. Society may also assign rank or status according to gender (i.e., men have a higher standing than women), which causes inequalities between genders that intersect with other social and economic inequalities. Discrimination based on gender often crosses, or intersects, with other societal factors such as ethnicity , disability , socioeconomic status , age, geographic location, gender identity , and sexual orientation (WHO, 2023). This is known as intersectionality , a concept that considers how multiple disadvantages can interact with clients individually and reflect the inequities and injustices at the systems level. Sexism, racism, classism, colonialism, heterosexism, and ableism are a few of the structures that result in systems-level oppression and privilege (Crenshaw, 1991).
Globally, gender norms negatively affect girls and women more than boys and men (Office of the High Commissioner for Human Rights [OHCHR], 2023). For example, over 575 million girls reside in countries where their basic rights related to education, health, and safety are violated as a consequence of inequitable gender norms (Save the Children, 2023). According to the OHCHR, gender stereotypes and discrimination, intersecting with other social and economic stereotypes, are particularly detrimental to women from minority or Indigenous groups, women with disabilities, women from lower caste groups or with lower economic status, and migrant women (OHCHR, 2023).
Boys and men may also be negatively affected by gender norms, particularly those that emphasize rigid notions of masculinity. For example, some gender norms may encourage young men to engage in risky practices such as smoking, unprotected sexual behavior, and alcohol use and abuse, and it may make them less likely than women to seek medical attention (WHO, 2023). Some conceptions of masculinity lead males to commit violence against women and make men subject to violence perpetrated by other men. These pressures may lead some individuals to develop mental health issues (WHO, 2023).
Individuals who identify as gender diverse or transgender also experience negative consequences related to gender. Gender-diverse individuals do not conform to conventional gender norms of being a man or a woman, or they may not “place themselves in the male/female binary” (OHCHR, 2023, para 1). Individuals who are transgender identify with a different sex than the one assigned to them at birth. Globally, both groups experience marginalization, exclusion, violence, discrimination, and other human rights violations related to their gender identities (OHCHR, 2023).
Gender affects people’s experiences with and access to health care. How health services are organized and provided may either enable a person’s access to health care services, information, and support or hinder it (WHO, 2023). Women’s health and well-being is placed at risk because of gender inequality and discrimination. Women more frequently face barriers to accessing health information and services than men. Throughout the world, women face restrictions on movement in the health care system, lack of access to decision-making power, low health literacy rates, discriminatory attitudes of communities and health care providers, and a lack of training among health care providers specific to the health care needs and challenges they face (WHO, 2023).
Findings from a recent survey on women’s experiences with the U.S. health care system are consistent with the WHO’s conclusions. For example, 29 percent of U.S. women aged 18–64 who were surveyed reported their doctor dismissed their concerns, and another 15 percent reported their provider did not believe they were telling the truth (Long et al., 2023). Among survey participants aged 40–64, only 35 percent reported their health care provider discussed what to expect with menopause (Long et al., 2023). In another study, researchers used data from the CDC Behavioral Risk Factor Surveillance System (BRFSS) to study differences between males' and females’ ability to access medical care for atherosclerotic cardiovascular disease (ASCVD). They found that women were more likely to report a delay in accessing health care and an inability to see a health care provider or take prescribed medications due to cost than men (Daher et al., 2021).
Global health-related challenges females face include (WHO, 2023):
- Higher rates of unintended pregnancies for women and girls.
- Greater risk of developing diseases and conditions such as malnutrition, lower vision, and respiratory infections.
- Greater risk of experiencing elder abuse than older males.
- Higher rates of violence directed toward them when compared to males, which includes sexual and physical violence. Approximately one in three women worldwide have experienced either physical and/or sexual intimate partner violence or non-partner sexual violence in their lifetime.
- In some developing countries, women experience female genital mutilation and early and forced marriage.
Decades ago, the United States took an important step toward addressing gender disparities in medicine. In 1986, the National Institutes of Health (NIH) established a policy requiring that women be included as subjects of clinical research. The following year, the Food and Drug Administration (FDA) began requiring pharmaceutical companies to demonstrate medication safety and effectiveness by sex, age, and race (Office on Women's Health, 2020). Despite these policy gains, more work is needed; this video offers a glimpse of the impact of the persistent gender gap in today’s clinical drug trials.
Watch the video, and then respond to the following questions.
- Beyond the immediate physical effects the women in the video experienced, what other consequences could these women face?
- Knowledge gaps in medical research are a form of gender bias in health care. What other forms of gender bias against women exist in health care?
Special Considerations for the LGBTQIA+ Population
Research shows that the LGBTQIA+ population experiences poorer health outcomes compared to the cis-heterosexual population. In a systematic review of the literature, Medina-Martinez et al. (2021) found that as compared to the cis-heterosexual population, this community experiences higher rates of mental health problems, substance misuse, and suicide. They also found that certain cancers, including colon, liver, breast, ovarian, and cervical, are more prevalent among lesbian and bisexual women. Gay and bisexual men have higher rates of sexually transmitted infections, including HIV, as well as increased rates of anal, prostate, testicular, and colon cancers (Medina-Martinez et al., 2021). Compared with the general population, individuals who are transgender experience a higher prevalence and earlier onset of disabilities, more chronic health conditions, and higher rates of health problems related to AIDS, substance use, mental illness, and sexual and physical violence (Medina et al., 2021). For children and adolescents who identify as lesbian, gay, bisexual, transgender, questioning, or queer (LGBTQ), the risks of suicidal thoughts and behaviors is higher (AHRQ, 2022).
Along with the disease risks for members of the LGBTQIA+ population, there are the issues of homophobia, stigma, and discrimination regarding their identity (CDC, 2022c). Limited access to culturally appropriate and orientation-appropriate services can hinder treatment. Finally, members of this group may be fearful about talking about their gender identity and sexual orientation. LGBTQIA+ people face barriers when trying to access health care, including negative and discriminatory experiences with health care workers (Medina-Martinez et al., 2021). Transgender people often experience verbal and physical abuse, hostility, and refusal of care during their interactions with the health care system or with individual health care providers (Medina et al., 2021). See Caring for Vulnerable Populations and Communities for more information on health care challenges related to the LGBTQIA+ population.
Read the scenario, and then answer the questions that follow.
As part of her role as a registered nurse case manager for Medicaid clients, Marinelle works with pregnant clients to coordinate their prenatal care. These clients are part of a group that has been identified as high risk for pregnancy-related complications. For the past few months, Marinelle has tracked her clients’ prenatal appointments and detects a trend in missed appointments. Most clients who miss appointments live in the same area of the county. It is a small rural neighborhood located in the vicinity of an abandoned factory. All the clients are Black women.
1. Which of the following factors should the nurse consider as most likely contributing to the clients’ poor pregnancy-related outcomes?
- Genetics
- Biological factors
- Cultural environment
- Physical environment
2. One aspect of health care access is clients’ ability to attend scheduled appointments. Which of the following factors is most likely to facilitate clients’ ability to access health care?
- Having a chronic disease
- Having adequate insurance coverage
- Having strong social support
- Having the ability to take time off work for appointments


2.2: Case Study - Amazon in 2023 by Sunil Gupta and Margaret L. Rodriguez
I like to bring in the Harvard Business Publishing case “Amazon in 2023” by Sunil Gupta and Margaret Rodriguez to give students a solid, real-world example.
Abstract: Amazon kicked off its journey in July 1995, selling books online. Fast forward to 2020, and it’s a digital behemoth raking in over $280 billion in yearly sales. A significant chunk of its growth comes from branching out into various businesses that some might consider unrelated.
Now, your students might not have access to the actual case, but let me break down some core concepts from the authors, so everyone can grasp the essentials without the case. Plus, this’ll help anyone teaching with the textbook to integrate the case more effectively.
In today’s market landscape, broad differentiation – being cheaper or better – is no longer enough to succeed. The digital era requires businesses to connect consumers and products through network effects and complementary offerings. This “winner-take-all” strategy creates connections between different industries, as seen with Amazon Studios videos offered for free with Prime memberships, leading to increased spending on their e-commerce platform.
Sunil Gupta, a professor at Harvard Business School, has spent over 12 years researching how technologies are changing consumer behavior and business strategies. His case study “Amazon in 2023” examines Amazon’s expansion into seemingly unrelated businesses and raises questions about whether this lack of focus is detrimental or if it’s positioning the company for future success.
Gupta emphasizes that differentiation alone is not enough in the digital era. Instead, businesses need to connect consumers and products through network effects and complementary offerings. This approach allows companies to be a “razor” in one industry and a “blade” in another, such as Amazon offering free videos through Prime to increase spending on their e-commerce platform.
When teaching this case, Gupta encourages pushing students to think more deeply about Amazon’s various ventures and question who the company is competing with. This case study can be easily taught online and appeals to a wide range of student groups. The key is to enjoy the case, stay updated on the latest developments, and engage in meaningful discussions about Amazon’s evolving strategies.
In this 2010 interview with Charlie Rose, Jeff Bezos, the founder and former CEO of Amazon, shares his insights on Amazon’s competitive advantage, how they approach competition. Bezos explains that Amazon’s approach to maintaining a competitive edge consists of three key factors: a wide selection, low prices, and fast, convenient, reliable delivery. He also emphasizes the importance of being customer-obsessed, focusing on the customer more than on competitors. Bezos highlights that Amazon’s online business model allows for cost structure advantages and that their purchasing power is now comparable to that of Walmart.
You will find more infographics at Statista
- What business is Amazon in? Are they spreading themselves too thin or are they well-positioned for the future?
- Who are Amazon’s competitors? And what is Amazon’s competitive advantage?
- What should traditional retailers like Best Buy do to compete with Amazon?


20.4: Transmutation and Nuclear Energy
↵
- Describe the synthesis of transuranium nuclides
- Explain nuclear fission and fusion processes
- Relate the concepts of critical mass and nuclear chain reactions
- Summarize basic requirements for nuclear fission and fusion reactors
After the discovery of radioactivity, the field of nuclear chemistry was created and developed rapidly during the early twentieth century. A slew of new discoveries in the 1930s and 1940s, along with World War II , combined to usher in the Nuclear Age in the mid-twentieth century. Science learned how to create new substances, and certain isotopes of certain elements were found to possess the capacity to produce unprecedented amounts of energy, with the potential to cause tremendous damage during war, as well as produce enormous amounts of power for society’s needs during peace.
Synthesis of Nuclides
Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with another particle. The first manmade nucleus was produced in Ernest Rutherford’s laboratory in 1919 by a transmutation reaction, the bombardment of one type of nuclei with other nuclei or with neutrons. Rutherford bombarded nitrogen atoms with high-speed α particles from a natural radioactive isotope of radium and observed protons resulting from the reaction:
\[\ce{^{14}_7N + ^4_2He ⟶ ^{17}_8O + ^1_1H} \nonumber \]
The \(\ce{^{17}_8O}\) and \(\ce{^1_1H}\) nuclei that are produced are stable, so no further (nuclear) changes occur.
To reach the kinetic energies necessary to produce transmutation reactions, devices called particle accelerators are used. These devices use magnetic and electric fields to increase the speeds of nuclear particles. In all accelerators, the particles move in a vacuum to avoid collisions with gas molecules. When neutrons are required for transmutation reactions, they are usually obtained from radioactive decay reactions or from various nuclear reactions occurring in nuclear reactors. The Chemistry in Everyday Life feature that follows discusses a famous particle accelerator that made worldwide news.
Located near Geneva, the CERN (“Conseil Européen pour la Recherche Nucléaire,” or European Council for Nuclear Research) Laboratory is the world’s premier center for the investigations of the fundamental particles that make up matter. It contains the 27-kilometer (17 mile) long, circular Large Hadron Collider (LHC), the largest particle accelerator in the world (Figure \(\PageIndex{1}\)). In the LHC , particles are boosted to high energies and are then made to collide with each other or with stationary targets at nearly the speed of light. Superconducting electromagnets are used to produce a strong magnetic field that guides the particles around the ring. Specialized, purpose-built detectors observe and record the results of these collisions, which are then analyzed by CERN scientists using powerful computers.
In 2012, CERN announced that experiments at the LHC showed the first observations of the Higgs boson, an elementary particle that helps explain the origin of mass in fundamental particles. This long-anticipated discovery made worldwide news and resulted in the awarding of the 2103 Nobel Prize in Physics to François Englert and Peter Higgs, who had predicted the existence of this particle almost 50 years previously.
Prior to 1940, the heaviest-known element was uranium, whose atomic number is 92. Now, many artificial elements have been synthesized and isolated, including several on such a large scale that they have had a profound effect on society. One of these—element 93, neptunium (Np)—was first made in 1940 by McMillan and Abelson by bombarding uranium-238 with neutrons. The reaction creates unstable uranium-239, with a half-life of 23.5 minutes, which then decays into neptunium-239. Neptunium-239 is also radioactive, with a half-life of 2.36 days, and it decays into plutonium-239. The nuclear reactions are:
\[\begin{align*}
\ce{^{238}_{92}U + ^1_0n &⟶ ^{239}_{92}U} && \\[4pt]
&\ce{^{239}_{92}U &⟶ ^{239}_{93}Np + ^0_{−1}e \,\,\,\mathit{t}_{1/2}} &&\textrm{half-life}=\mathrm{23.5\: min} \\[4pt]
&\ce{^{239}_{93}Np &⟶ ^{239}_{94}Pu + ^0_{−1}e\,\,\, \mathit{t}_{1/2}} &&\textrm{half-life}=\mathrm{2.36\: days}
\end{align*} \nonumber \]
Plutonium is now mostly formed in nuclear reactors as a byproduct during the decay of uranium. Some of the neutrons that are released during U-235 decay combine with U-238 nuclei to form uranium-239; this undergoes β decay to form neptunium-239, which in turn undergoes β decay to form plutonium-239 as illustrated in the preceding three equations. It is possible to summarize these equations as:
\[\mathrm{\ce{^{238}_{92}U} + {^1_0n}⟶ \ce{^{239}_{92}U} \xrightarrow{β^-} \ce{^{239}_{93}Np} \xrightarrow{β^-} \ce{^{239}_{94}Pu}} \nonumber \]
Heavier isotopes of plutonium—Pu-240, Pu-241, and Pu-242—are also produced when lighter plutonium nuclei capture neutrons. Some of this highly radioactive plutonium is used to produce military weapons, and the rest presents a serious storage problem because they have half-lives from thousands to hundreds of thousands of years.
Although they have not been prepared in the same quantity as plutonium, many other synthetic nuclei have been produced. Nuclear medicine has developed from the ability to convert atoms of one type into other types of atoms. Radioactive isotopes of several dozen elements are currently used for medical applications. The radiation produced by their decay is used to image or treat various organs or portions of the body, among other uses.
The elements beyond element 92 (uranium) are called transuranium elements . As of this writing, 22 transuranium elements have been produced and officially recognized by IUPAC; several other elements have formation claims that are waiting for approval. Some of these elements are shown in Table \(\PageIndex{1}\).
| Name | Symbol | Atomic Number | Reaction |
|---|---|---|---|
| americium | Am | 95 | \(\ce{^{239}_{94}Pu + ^1_0n ⟶ ^{240}_{95}Am + ^0_{−1}e}\) |
| curium | Cm | 96 | \(\ce{^{239}_{94}Pu + ^4_2He ⟶ ^{242}_{96}Cm + ^1_0n}\) |
| californium | Cf | 98 | \(\ce{^{242}_{96}Cm + ^4_2He⟶ ^{245}_{98}Cf + ^1_0n}\) |
| einsteinium | Es | 99 | \(\ce{^{238}_{92}U + 15^1_0n⟶ ^{253}_{99}Es + 7^0_{−1}e}\) |
| mendelevium | Md | 101 | \(\ce{^{253}_{99}Es + ^4_2He ⟶ ^{256}_{101}Md + ^1_0n}\) |
| nobelium | No | 102 | \(\ce{^{246}_{96}Cm + ^{12}_6C ⟶ ^{254}_{102}No + 4 ^1_0n}\) |
| rutherfordium | Rf | 104 | \(\ce{^{249}_{98}Cf + ^{12}_6C⟶ ^{257}_{104}Rf + 4 ^1_0n}\) |
|
seaborgium |
Sg |
106 |
\(\ce{^{206}_{82}Pb + ^{54}_{24}Cr ⟶ ^{257}_{106}Sg + 3 ^1_0n}\) \(\ce{^{249}_{98}Cf + ^{18}_8O ⟶ ^{263}_{106}Sg + 4 ^1_0n}\) |
| meitnerium | Mt | 107 | \(\ce{^{209}_{83}Bi + ^{58}_{26}Fe ⟶ ^{266}_{109}Mt + ^1_0n}\) |
Nuclear Fission
Many heavier elements with smaller binding energies per nucleon can decompose into more stable elements that have intermediate mass numbers and larger binding energies per nucleon—that is, mass numbers and binding energies per nucleon that are closer to the “peak” of the binding energy graph near 56. Sometimes neutrons are also produced. This decomposition is called fission , the breaking of a large nucleus into smaller pieces. The breaking is rather random with the formation of a large number of different products. Fission usually does not occur naturally, but is induced by bombardment with neutrons. The first reported nuclear fission occurred in 1939 when three German scientists, Lise Meitner, Otto Hahn, and Fritz Strassman, bombarded uranium-235 atoms with slow-moving neutrons that split the U-238 nuclei into smaller fragments that consisted of several neutrons and elements near the middle of the periodic table. Since then, fission has been observed in many other isotopes, including most actinide isotopes that have an odd number of neutrons. A typical nuclear fission reaction is shown in Figure \(\PageIndex{2}\).
Among the products of Meitner, Hahn, and Strassman’s fission reaction were barium, krypton, lanthanum, and cerium, all of which have nuclei that are more stable than uranium-235. Since then, hundreds of different isotopes have been observed among the products of fissionable substances. A few of the many reactions that occur for U-235, and a graph showing the distribution of its fission products and their yields, are shown in Figure \(\PageIndex{3}\). Similar fission reactions have been observed with other uranium isotopes, as well as with a variety of other isotopes such as those of plutonium.
A tremendous amount of energy is produced by the fission of heavy elements. For instance, when one mole of U-235 undergoes fission, the products weigh about 0.2 grams less than the reactants; this “lost” mass is converted into a very large amount of energy, about 1.8 × 10 10 kJ per mole of U-235. Nuclear fission reactions produce incredibly large amounts of energy compared to chemical reactions. The fission of 1 kilogram of uranium-235, for example, produces about 2.5 million times as much energy as is produced by burning 1 kilogram of coal.
As described earlier, when undergoing fission U-235 produces two “medium-sized” nuclei, and two or three neutrons. These neutrons may then cause the fission of other uranium-235 atoms, which in turn provide more neutrons that can cause fission of even more nuclei, and so on. If this occurs, we have a nuclear chain re action (Figure \(\PageIndex{4}\)). On the other hand, if too many neutrons escape the bulk material without interacting with a nucleus, then no chain reaction will occur.
Material that can sustain a nuclear fission chain reaction is said to be fissile or fissionable . (Technically, fissile material can undergo fission with neutrons of any energy, whereas fissionable material requires high-energy neutrons.) Nuclear fission becomes self-sustaining when the number of neutrons produced by fission equals or exceeds the number of neutrons absorbed by splitting nuclei plus the number that escape into the surroundings. The amount of a fissionable material that will support a self-sustaining chain reaction is a critical mass . An amount of fissionable material that cannot sustain a chain reaction is a subcritical mass . An amount of material in which there is an increasing rate of fission is known as a supercritical mass . The critical mass depends on the type of material: its purity, the temperature, the shape of the sample, and how the neutron reactions are controlled (Figure \(\PageIndex{5}\)).
An atomic bomb (Figure \(\PageIndex{6}\)) contains several pounds of fissionable material, \(\ce{^{235}_{92}U}\) or \(\ce{^{239}_{94}Pu}\), a source of neutrons, and an explosive device for compressing it quickly into a small volume. When fissionable material is in small pieces, the proportion of neutrons that escape through the relatively large surface area is great, and a chain reaction does not take place. When the small pieces of fissionable material are brought together quickly to form a body with a mass larger than the critical mass, the relative number of escaping neutrons decreases, and a chain reaction and explosion result.
Fission Reactors
Chain reactions of fissionable materials can be controlled and sustained without an explosion in a nuclear reactor (Figure \(\PageIndex{7}\)). Any nuclear reactor that produces power via the fission of uranium or plutonium by bombardment with neutrons must have at least five components: nuclear fuel consisting of fissionable material, a nuclear moderator, reactor coolant, control rods, and a shield and containment system. We will discuss these components in greater detail later in the section. The reactor works by separating the fissionable nuclear material such that a critical mass cannot be formed, controlling both the flux and absorption of neutrons to allow shutting down the fission reactions. In a nuclear reactor used for the production of electricity, the energy released by fission reactions is trapped as thermal energy and used to boil water and produce steam. The steam is used to turn a turbine, which powers a generator for the production of electricity.
Nuclear Fuels
Nuclear fuel consists of a fissionable isotope, such as uranium-235, which must be present in sufficient quantity to provide a self-sustaining chain reaction. In the United States, uranium ores contain from 0.05–0.3% of the uranium oxide U 3 O 8 ; the uranium in the ore is about 99.3% nonfissionable U-238 with only 0.7% fissionable U-235. Nuclear reactors require a fuel with a higher concentration of U-235 than is found in nature; it is normally enriched to have about 5% of uranium mass as U-235. At this concentration, it is not possible to achieve the supercritical mass necessary for a nuclear explosion. Uranium can be enriched by gaseous diffusion (the only method currently used in the US), using a gas centrifuge, or by laser separation.
In the gaseous diffusion enrichment plant where U-235 fuel is prepared, UF 6 (uranium hexafluoride) gas at low pressure moves through barriers that have holes just barely large enough for UF 6 to pass through. The slightly lighter 235 UF 6 molecules diffuse through the barrier slightly faster than the heavier 238 UF 6 molecules. This process is repeated through hundreds of barriers, gradually increasing the concentration of 235 UF 6 to the level needed by the nuclear reactor. The basis for this process, Graham’s law, is described in the chapter on gases. The enriched UF 6 gas is collected, cooled until it solidifies, and then taken to a fabrication facility where it is made into fuel assemblies. Each fuel assembly consists of fuel rods that contain many thimble-sized, ceramic-encased, enriched uranium (usually UO 2 ) fuel pellets. Modern nuclear reactors may contain as many as 10 million fuel pellets. The amount of energy in each of these pellets is equal to that in almost a ton of coal or 150 gallons of oil.
Nuclear Moderators
Neutrons produced by nuclear reactions move too fast to cause fission (Figure 21.5.5). They must first be slowed to be absorbed by the fuel and produce additional nuclear reactions.  Early reactors used high-purity graphite as a moderator. Modern reactors in the US exclusively use heavy water \(\ce{( ^2_1H2O)}\) or light water (ordinary H 2 O), whereas some reactors in other countries use other materials, such as carbon dioxide, beryllium, or graphite.
Reactor Coolants
A nuclear reactor coolant is used to carry the heat produced by the fission reaction to an external boiler and turbine, where it is transformed into electricity. Two overlapping coolant loops are often used; this counteracts the transfer of radioactivity from the reactor to the primary coolant loop. All nuclear power plants in the US use water as a coolant. Other coolants include molten sodium, lead, a lead-bismuth mixture, or molten salts.
Control Rods
Nuclear reactors use control rods (Figure \(\PageIndex{8}\)) to control the fission rate of the nuclear fuel by adjusting the number of slow neutrons present to keep the rate of the chain reaction at a safe level. Control rods are made of boron, cadmium, hafnium, or other elements that are able to absorb neutrons. Boron-10, for example, absorbs neutrons by a reaction that produces lithium-7 and alpha particles:
\[\ce{^{10}_5B + ^1_0n⟶ ^7_3Li + ^4_2He} \nonumber \]
When control rod assemblies are inserted into the fuel element in the reactor core, they absorb a larger fraction of the slow neutrons, thereby slowing the rate of the fission reaction and decreasing the power produced. Conversely, if the control rods are removed, fewer neutrons are absorbed, and the fission rate and energy production increase. In an emergency, the chain reaction can be shut down by fully inserting all of the control rods into the nuclear core between the fuel rods.
Shield and Containment System
During its operation, a nuclear reactor produces neutrons and other radiation. Even when shut down, the decay products are radioactive. In addition, an operating reactor is thermally very hot, and high pressures result from the circulation of water or another coolant through it. Thus, a reactor must withstand high temperatures and pressures, and must protect operating personnel from the radiation. Reactors are equipped with a containment system (or shield) that consists of three parts:
- The reactor vessel, a steel shell that is 3–20-centimeters thick and, with the moderator, absorbs much of the radiation produced by the reactor
- A main shield of 1–3 meters of high-density concrete
- A personnel shield of lighter materials that protects operators from γ rays and X-rays
In addition, reactors are often covered with a steel or concrete dome that is designed to contain any radioactive materials might be released by a reactor accident.
Nuclear power plants are designed in such a way that they cannot form a supercritical mass of fissionable material and therefore cannot create a nuclear explosion. But as history has shown, failures of systems and safeguards can cause catastrophic accidents, including chemical explosions and nuclear meltdowns (damage to the reactor core from overheating). The following Chemistry in Everyday Life feature explores three infamous meltdown incidents.
The importance of cooling and containment are amply illustrated by three major accidents that occurred with the nuclear reactors at nuclear power generating stations in the United States (Three Mile Island), the former Soviet Union (Chernobyl), and Japan (Fukushima).
In March 1979, the cooling system of the Unit 2 reactor at Three Mile Island Nuclear Generating Station in Pennsylvania failed, and the cooling water spilled from the reactor onto the floor of the containment building. After the pumps stopped, the reactors overheated due to the high radioactive decay heat produced in the first few days after the nuclear reactor shut down. The temperature of the core climbed to at least 2200 °C, and the upper portion of the core began to melt. In addition, the zirconium alloy cladding of the fuel rods began to react with steam and produced hydrogen:
\[\ce{Zr}(s)+\ce{2H2O}(g)⟶\ce{ZrO2}(s)+\ce{2H2}(g) \nonumber \]
The hydrogen accumulated in the confinement building, and it was feared that there was danger of an explosion of the mixture of hydrogen and air in the building. Consequently, hydrogen gas and radioactive gases (primarily krypton and xenon) were vented from the building. Within a week, cooling water circulation was restored and the core began to cool. The plant was closed for nearly 10 years during the cleanup process.
Although zero discharge of radioactive material is desirable, the discharge of radioactive krypton and xenon, such as occurred at the Three Mile Island plant, is among the most tolerable. These gases readily disperse in the atmosphere and thus do not produce highly radioactive areas. Moreover, they are noble gases and are not incorporated into plant and animal matter in the food chain. Effectively none of the heavy elements of the core of the reactor were released into the environment, and no cleanup of the area outside of the containment building was necessary (Figure \(\PageIndex{9}\)).
Another major nuclear accident involving a reactor occurred in April 1986, at the Chernobyl Nuclear Power Plant in Ukraine, which was still a part of the former Soviet Union. While operating at low power during an unauthorized experiment with some of its safety devices shut off, one of the reactors at the plant became unstable. Its chain reaction became uncontrollable and increased to a level far beyond what the reactor was designed for. The steam pressure in the reactor rose to between 100 and 500 times the full power pressure and ruptured the reactor. Because the reactor was not enclosed in a containment building, a large amount of radioactive material spewed out, and additional fission products were released, as the graphite (carbon) moderator of the core ignited and burned. The fire was controlled, but over 200 plant workers and firefighters developed acute radiation sickness and at least 32 soon died from the effects of the radiation. It is predicted that about 4000 more deaths will occur among emergency workers and former Chernobyl residents from radiation-induced cancer and leukemia. The reactor has since been encapsulated in steel and concrete, a now-decaying structure known as the sarcophagus. Almost 30 years later, significant radiation problems still persist in the area, and Chernobyl largely remains a wasteland.
In 2011, the Fukushima Daiichi Nuclear Power Plant in Japan was badly damaged by a 9.0-magnitude earthquake and resulting tsunami. Three reactors up and running at the time were shut down automatically, and emergency generators came online to power electronics and coolant systems. However, the tsunami quickly flooded the emergency generators and cut power to the pumps that circulated coolant water through the reactors. High-temperature steam in the reactors reacted with zirconium alloy to produce hydrogen gas. The gas escaped into the containment building, and the mixture of hydrogen and air exploded. Radioactive material was released from the containment vessels as the result of deliberate venting to reduce the hydrogen pressure, deliberate discharge of coolant water into the sea, and accidental or uncontrolled events.
An evacuation zone around the damaged plant extended over 12.4 miles away, and an estimated 200,000 people were evacuated from the area. All 48 of Japan’s nuclear power plants were subsequently shut down, remaining shuttered as of December 2014. Since the disaster, public opinion has shifted from largely favoring to largely opposing increasing the use of nuclear power plants, and a restart of Japan’s atomic energy program is still stalled (Figure \(\PageIndex{10}\)).
The energy produced by a reactor fueled with enriched uranium results from the fission of uranium as well as from the fission of plutonium produced as the reactor operates. As discussed previously, the plutonium forms from the combination of neutrons and the uranium in the fuel. In any nuclear reactor, only about 0.1% of the mass of the fuel is converted into energy. The other 99.9% remains in the fuel rods as fission products and unused fuel. All of the fission products absorb neutrons, and after a period of several months to a few years, depending on the reactor, the fission products must be removed by changing the fuel rods. Otherwise, the concentration of these fission products would increase and absorb more neutrons until the reactor could no longer operate.
Spent fuel rods contain a variety of products, consisting of unstable nuclei ranging in atomic number from 25 to 60, some transuranium elements, including plutonium and americium, and unreacted uranium isotopes. The unstable nuclei and the transuranium isotopes give the spent fuel a dangerously high level of radioactivity. The long-lived isotopes require thousands of years to decay to a safe level. The ultimate fate of the nuclear reactor as a significant source of energy in the United States probably rests on whether or not a politically and scientifically satisfactory technique for processing and storing the components of spent fuel rods can be developed.
Nuclear Fusion and Fusion Reactors
The process of converting very light nuclei into heavier nuclei is also accompanied by the conversion of mass into large amounts of energy, a process called fusion . The principal source of energy in the sun is a net fusion reaction in which four hydrogen nuclei fuse and produce one helium nucleus and two positrons. This is a net reaction of a more complicated series of events:
\[\ce{4^1_1H ⟶ ^4_2He + 2^0_{+1}} \nonumber \]
A helium nucleus has a mass that is 0.7% less than that of four hydrogen nuclei; this lost mass is converted into energy during the fusion. This reaction produces about 3.6 × 10 11 kJ of energy per mole of \(\ce{^4_2He}\) produced. This is somewhat larger than the energy produced by the nuclear fission of one mole of U-235 (1.8 × 10 10 kJ), and over 3 million times larger than the energy produced by the (chemical) combustion of one mole of octane (5471 kJ).
It has been determined that the nuclei of the heavy isotopes of hydrogen, a deuteron, \(^2_1\) and a triton, \(^3_1\), undergo fusion at extremely high temperatures (thermonuclear fusion). They form a helium nucleus and a neutron:
\[\ce{^2_1H + ^3_1H ⟶ ^4_2He + 2^1_0n} \nonumber \]
This change proceeds with a mass loss of 0.0188 amu, corresponding to the release of 1.69 × 10 9 kilojoules per mole of \(\ce{^4_2He}\) formed. The very high temperature is necessary to give the nuclei enough kinetic energy to overcome the very strong repulsive forces resulting from the positive charges on their nuclei so they can collide.
Useful fusion reactions require very high temperatures for their initiation—about 15,000,000 K or more. At these temperatures, all molecules dissociate into atoms, and the atoms ionize, forming plasma. These conditions occur in an extremely large number of locations throughout the universe—stars are powered by fusion. Humans have already figured out how to create temperatures high enough to achieve fusion on a large scale in thermonuclear weapons. A thermonuclear weapon such as a hydrogen bomb contains a nuclear fission bomb that, when exploded, gives off enough energy to produce the extremely high temperatures necessary for fusion to occur.
Another much more beneficial way to create fusion reactions is in a fusion reactor , a nuclear reactor in which fusion reactions of light nuclei are controlled. Because no solid materials are stable at such high temperatures, mechanical devices cannot contain the plasma in which fusion reactions occur. Two techniques to contain plasma at the density and temperature necessary for a fusion reaction are currently the focus of intensive research efforts: containment by a magnetic field and by the use of focused laser beams (Figure \(\PageIndex{11}\)). A number of large projects are working to attain one of the biggest goals in science: getting hydrogen fuel to ignite and produce more energy than the amount supplied to achieve the extremely high temperatures and pressures that are required for fusion. At the time of this writing, there are no self-sustaining fusion reactors operating in the world, although small-scale controlled fusion reactions have been run for very brief periods.
Summary
It is possible to produce new atoms by bombarding other atoms with nuclei or high-speed particles. The products of these transmutation reactions can be stable or radioactive. A number of artificial elements, including technetium, astatine, and the transuranium elements, have been produced in this way.
Nuclear power as well as nuclear weapon detonations can be generated through fission (reactions in which a heavy nucleus is split into two or more lighter nuclei and several neutrons). Because the neutrons may induce additional fission reactions when they combine with other heavy nuclei, a chain reaction can result. Useful power is obtained if the fission process is carried out in a nuclear reactor. The conversion of light nuclei into heavier nuclei (fusion) also produces energy. At present, this energy has not been contained adequately and is too expensive to be feasible for commercial energy production.
Glossary
- chain reaction
- repeated fission caused when the neutrons released in fission bombard other atoms
- containment system
- (also, shield) a three-part structure of materials that protects the exterior of a nuclear fission reactor and operating personnel from the high temperatures, pressures, and radiation levels inside the reactor
- control rod
- material inserted into the fuel assembly that absorbs neutrons and can be raised or lowered to adjust the rate of a fission reaction
- critical mass
- amount of fissionable material that will support a self-sustaining (nuclear fission) chain reaction
- fissile (or fissionable)
- when a material is capable of sustaining a nuclear fission reaction
- fission
- splitting of a heavier nucleus into two or more lighter nuclei, usually accompanied by the conversion of mass into large amounts of energy
- fusion
- combination of very light nuclei into heavier nuclei, accompanied by the conversion of mass into large amounts of energy
- fusion reactor
- nuclear reactor in which fusion reactions of light nuclei are controlled
- nuclear fuel
- fissionable isotope present in sufficient quantities to provide a self-sustaining chain reaction in a nuclear reactor
- nuclear moderator
- substance that slows neutrons to a speed low enough to cause fission
- nuclear reactor
- environment that produces energy via nuclear fission in which the chain reaction is controlled and sustained without explosion
- nuclear transmutation
- conversion of one nuclide into another nuclide
- particle accelerator
- device that uses electric and magnetic fields to increase the kinetic energy of nuclei used in transmutation reactions
- reactor coolant
- assembly used to carry the heat produced by fission in a reactor to an external boiler and turbine where it is transformed into electricity
- subcritical mass
- amount of fissionable material that cannot sustain a chain reaction; less than a critical mass
- supercritical mass
- amount of material in which there is an increasing rate of fission
- transmutation reaction
- bombardment of one type of nuclei with other nuclei or neutrons
- transuranium element
- element with an atomic number greater than 92; these elements do not occur in nature