7: Does IT Matter?
Learning Objectives
Upon successful completion of this chapter, you will be able to:
- define the productivity paradox and explain the current thinking on this topic;
- evaluate Carr’s argument in “Does IT Matter?”;
- describe the components of competitive advantage; and
- describe information systems that can provide businesses with competitive advantage.
Introduction
For over fifty years, computing technology has been a part of business. Organizations have spent trillions of dollars on information technologies. But has all this investment in IT made a difference? Have we seen increases in productivity? Are companies that invest in IT more competitive? In this chapter, we will look at the value IT can bring to an organization and try to answer these questions. We will begin by highlighting two important works from the past two decades.
The Productivity Paradox
In 1991, Erik Brynjolfsson wrote an article, published in the Communications of the ACM , entitled “ The Productivity Paradox of Information Technology: Review and Assessment .” By reviewing studies about the impact of IT investment on productivity, Brynjolfsson was able to conclude that the addition of information technology to business had not improved productivity at all – the “productivity paradox.” From the article [1] He does not draw any specific conclusions from this finding, and provides the following analysis:
Although it is too early to conclude that IT’s productivity contribution has been subpar, a paradox remains in our inability to unequivocally document any contribution after so much effort. The various explanations that have been proposed can be grouped into four categories:
- Mismeasurement of outputs and inputs,
- Lags due to learning and adjustment,
- Redistribution and dissipation of profits,
- Mismanagement of information and technology.
In 1998, Brynjolfsson and Lorin Hitt published a follow-up paper entitled “ Beyond the Productivity Paradox .” [2] In this paper, the authors utilized new data that had been collected and found that IT did, indeed, provide a positive result for businesses. Further, they found that sometimes the true advantages in using technology were not directly relatable to higher productivity, but to “softer” measures, such as the impact on organizational structure. They also found that the impact of information technology can vary widely between companies.
IT Doesn’t Matter
Just as a consensus was forming about the value of IT, the Internet stock market bubble burst. Just two years later, in 2003, Harvard professor Nicholas Carr wrote his article “ IT Doesn’t Matter ” in the Harvard Business Review. In this article Carr asserts that as information technology has become more ubiquitous, it has also become less of a differentiator. In other words: because information technology is so readily available and the software used so easily copied, businesses cannot hope to implement these tools to provide any sort of competitive advantage. Carr goes on to suggest that since IT is essentially a commodity, it should be managed like one: low cost, low risk. Using the analogy of electricity, Carr describes how a firm should never be the first to try a new technology, thereby letting others take the risks . IT management should see themselves as a utility within the company and work to keep costs down . For IT, providing the best service with minimal downtime is the goal.
As you can imagine, this article caused quite an uproar, especially from IT companies. Many articles were written in defense of IT; many others in support of Carr. Carr released a book based on the article in 2004, entitled Does IT Matter? Click here to watch a video of Carr being interviewed about his book on CNET.
Probably the best thing to come out of the article and subsequent book was that it opened up discussion on the place of IT in a business strategy, and exactly what role IT could play in competitive advantage. It is that question that we want to address in the rest of the this chapter.
[Embed "IT Doesn't Matter" classroom video footage here: http://quickstream.biola.edu/distanc...n'tMatter.f4v]
Competitive Advantage
What does it mean when a company has a competitive advantage? What are the factors that play into it? While there are entire courses and many different opinions on this topic, let’s go with one of the most accepted definitions, developed by Michael Porter in his book Competitive Advantage: Creating and Sustaining Superior Performance. A company is said to have a competitive advantage over its rivals when it is able to sustain profits that exceed average for the industry. According to Porter, there are two primary methods for obtaining competitive advantage: cost advantage and differentiation advantage. So the question becomes: how can information technology be a factor in one or both of these methods? In the sections below we will explore this question using two of Porter’s analysis tools: the value chain and the five forces model. We will also use Porter’s analysis in his 2001 article “Strategy and the Internet,” which examines the impact of the Internet on business strategy and competitive advantage, to shed further light on the role of information technology in competitive advantage.
The Value Chain
In his book, Porter describes exactly how a company can create value (and therefore profit). Value is built through the value chain: a series of activities undertaken by the company to produce a product or service. Each step in the value chain contributes to the overall value of a product or service. While the value chain may not be a perfect model for every type of company, it does provide a way to analyze just how a company is producing value. The value chain is made up of two sets of activities: primary activities and support activities. We will briefly examine these activities and discuss how information technology can play a role in creating value by contributing to cost advantage or differentiation advantage, or both.
Porter’s value chain
The primary activities are the functions that directly impact the creation of a product or service. The goal of the primary activities is to add more value than they cost. The primary activities are:
- Inbound logistics: These are the functions performed to bring in raw materials and other needed inputs. Information technology can be used here to make these processes more efficient, such as with supply-chain management systems, which allow the suppliers to manage their own inventory.
- Operations: Any part of a business that is involved in converting the raw materials into the final products or services is part of operations. From manufacturing to business process management (covered in chapter 8), information technology can be used to provide more efficient processes and increase innovation through flows of information.
- Outbound logistics: These are the functions required to get the product out to the customer. As with inbound logistics, IT can be used here to improve processes, such as allowing for real-time inventory checks. IT can also be a delivery mechanism itself.
- Sales/Marketing: The functions that will entice buyers to purchase the products are part of sales and marketing. Information technology is used in almost all aspects of this activity. From online advertising to online surveys, IT can be used to innovate product design and reach customers like never before. The company website can be a sales channel itself.
- Service: The functions a business performs after the product has been purchased to maintain and enhance the product’s value are part of the service activity. Service can be enhanced via technology as well, including support services through websites and knowledge bases.
The support activities are the functions in an organization that support, and cut across, all of the primary activities. The support activities are:
- Firm infrastructure: This includes organizational functions such as finance, accounting, and quality control, all of which depend on information technology; the use of ERP systems (to be covered in chapter 9) is a good example of the impact that IT can have on these functions.
- Human resource management: This activity consists of recruiting, hiring, and other services needed to attract and retain employees. Using the Internet, HR departments can increase their reach when looking for candidates. There is also the possibility of allowing employees to use technology for a more flexible work environment.
- Technology development: Here we have the technological advances and innovations that support the primary activities. These advances are then integrated across the firm or within one of the primary activities to add value. Information technology would fall specifically under this activity.
- Procurement: The activities involved in acquiring the raw materials used in the creation of products and services are called procurement. Business-to-business e-commerce can be used to improve the acquisition of materials.
This analysis of the value chain provides some insight into how information technology can lead to competitive advantage. Let’s now look at another tool that Porter developed – the “five forces” model.
Porter’s Five Forces
Porter developed the “five forces” model as a framework for industry analysis. This model can be used to help understand just how competitive an industry is and to analyze its strengths and weaknesses. The model consists of five elements, each of which plays a role in determining the average profitability of an industry.
Porter’s five forces
In 2001, Porter wrote an article entitled ”Strategy and the Internet,” in which he takes this model and looks at how the Internet impacts the profitability of an industry. Below is a quick summary of each of the five forces and the impact of the Internet.
- Threat of substitute products or services: How easily can a product or service be replaced with something else? The more types of products or services there are that can meet a particular need, the less profitability there will be in an industry. For example, the advent of the mobile phone has replaced the need for pagers. The Internet has made people more aware of substitute products, driving down industry profits in those industries being substituted.
- Bargaining power of suppliers: When a company has several suppliers to choose from, it can demand a lower price. When a sole supplier exists, then the company is at the mercy of the supplier. For example, if only one company makes the controller chip for a car engine, that company can control the price, at least to some extent. The Internet has given companies access to more suppliers, driving down prices. On the other hand, suppliers now also have the ability to sell directly to customers.
- Bargaining power of customers: A company that is the sole provider of a unique product has the ability to control pricing. But the Internet has given customers many more options to choose from.
- B arriers to entry: The easier it is to enter an industry, the tougher it will be to make a profit in that industry. The Internet has an overall effect of making it easier to enter industries. It is also very easy to copy technology, so new innovations will not last that long.
- Rivalry among existing competitors: The more competitors there are in an industry, the bigger a factor price becomes. The advent of the Internet has increased competition by widening the geographic market and lowering the costs of doing business. For example, a manufacturer in Southern California may now have to compete against a manufacturer in the South, where wages are lower.
Porter’s five forces are used to analyze an industry to determine the average profitability of a company within that industry. Adding in Porter’s analysis of the Internet, we can see that the Internet (and by extension, information technology in general) has the effect of lowering overall profitability. [3] While the Internet has certainly produced many companies that are big winners, the overall winners have been the consumers, who have been given an ever-increasing market of products and services and lower prices.
Using Information Systems for Competitive Advantage
Now that we have an understanding of competitive advantage and some of the ways that IT may be used to help organizations gain it, we will turn our attention to some specific examples. A strategic information system is an information system that is designed specifically to implement an organizational strategy meant to provide a competitive advantage. These sorts of systems began popping up in the 1980s, as noted in a paper by Charles Wiseman entitled “Creating Competitive Weapons From Information Systems.” [4]
Specifically, a strategic information system is one that attempts to do one or more of the following:
- deliver a product or a service at a lower cost;
- deliver a product or service that is differentiated;
- help an organization focus on a specific market segment;
- enable innovation.
Following are some examples of information systems that fall into this category.
Business Process Management Systems
In their book, IT Doesn’t Matter – Business Processes Do , Howard Smith and Peter Fingar argue that it is the integration of information systems with business processes that leads to competitive advantage. They then go on to state that Carr’s article is dangerous because it gave CEOs and IT managers the green light to start cutting their technology budgets, putting their companies in peril. They go on to state that true competitive advantage can be found with information systems that support business processes. In chapter 8 we will focus on the use of business processes for competitive advantage.
Electronic Data Interchange
One of the ways that information systems have participated in competitive advantage is through integrating the supply chain electronically. This is primarily done through a process called electronic data interchange, or EDI. EDI can be thought of as the computer-to-computer exchange of business documents in a standard electronic format between business partners. By integrating suppliers and distributors via EDI, a company can vastly reduce the resources required to manage the relevant information. Instead of manually ordering supplies, the company can simply place an order via the computer and the next time the order process runs, it is ordered.
Collaborative Systems
As organizations began to implement networking technologies, information systems emerged that allowed employees to begin collaborating in different ways. These systems allowed users to brainstorm ideas together without the necessity of physical, face-to-face meetings. Utilizing tools such as discussion boards, document sharing, and video, these systems made it possible for ideas to be shared in new ways and the thought processes behind these ideas to be documented.
Broadly speaking, any software that allows multiple users to interact on a document or topic could be considered collaborative. Electronic mail, a shared Word document, social networks, and discussion boards would fall into this broad definition. However, many software tools have been created that are designed specifically for collaborative purposes. These tools offer a broad spectrum of collaborative functions. Here is just a short list of some collaborative tools available for businesses today:
- Google Drive . Google Drive offers a suite of office applications (such as a word processor, spreadsheet, drawing, presentation) that can be shared between individuals. Multiple users can edit the documents at the same time and threaded comments are available.
- Microsoft SharePoint . SharePoint integrates with Microsoft Office and allows for collaboration using tools most office workers are familiar with. SharePoint was covered in more detail in chapter 5.
- Cisco WebEx . WebEx is a business communications platform that combines video and audio communications and allows participants to interact with each other’s computer desktops. WebEx also provides a shared whiteboard and the capability for text-based chat to be going on during the sessions, along with many other features. Mobile editions of WebEx allow for full participation using smartphones and tablets.
- Atlassian Confluence . Confluence provides an all-in-one project-management application that allows users to collaborate on documents and communicate progress. The mobile edition of Confluence allows the project members to stay connected throughout the project.
- IBM Lotus Notes/Domino . One of the first true “groupware” collaboration tools, Lotus Notes (and its web-based cousin, Domino) provides a full suite of collaboration software, including integrated e-mail.
Decision Support Systems
A decision support system (DSS) is an information system built to help an organization make a specific decision or set of decisions. DSSs can exist at different levels of decision-making with the organization, from the CEO to the first-level managers. These systems are designed to take inputs regarding a known (or partially-known) decision-making process and provide the information necessary to make a decision. DSSs generally assist a management-level person in the decision-making process, though some can be designed to automate decision-making.
An organization has a wide variety of decisions to make , ranging from highly structured decisions to unstructured decisions. A structured decision is usually one that is made quite often, and one in which the decision is based directly on the inputs. With structured decisions, once you know the necessary information you also know the decision that needs to be made. For example, inventory reorder levels can be structured decisions: once our inventory of widgets gets below a specific threshold, automatically reorder ten more. Structured decisions are good candidates for automation, but we don’t necessarily build decision-support systems for them.
An unstructured decision involves a lot of unknowns. Many times, unstructured decisions are decisions being made for the first time. An information system can support these types of decisions by providing the decision-maker(s) with information-gathering tools and collaborative capabilities. An example of an unstructured decision might be dealing with a labor issue or setting policy for a new technology.
Decision support systems work best when the decision-maker(s) are making semi-structured decisions. A semi-structured decision is one in which most of the factors needed for making the decision are known but human experience and other outside factors may still play a role. A good example of an semi-structured decision would be diagnosing a medical condition (see sidebar).
As with collaborative systems, DSSs can come in many different formats. A nicely designed spreadsheet that allows for input of specific variables and then calculates required outputs could be considered a DSS. Another DSS might be one that assists in determining which products a company should develop. Input into the system could include market research on the product, competitor information, and product development costs. The system would then analyze these inputs based on the specific rules and concepts programmed into it. Finally, the system would report its results, with recommendations and/or key indicators to be used in making a decision. A DSS can be looked at as a tool for competitive advantage in that it can give an organization a mechanism to make wise decisions about products and innovations.
Sidebar: Isabel – A Health Care DSS
A discussed in the text, DSSs are best applied to semi-structured decisions, in which most of the needed inputs are known but human experience and environmental factors also play a role. A good example that is in use today is Isabel , a health care DSS. The creators of Isabel explain how it works:
Isabel uses the information routinely captured during your workup, whether free text or structured data, and instantaneously provides a diagnosis checklist for review. The checklist contains a list of possible diagnoses with critical “Don’t Miss Diagnoses” flagged. When integrated into your EMR system Isabel can provide “one click” seamless diagnosis support with no additional data entry. [5]
Investing in IT for Competitive Advantage
In 2008, Brynjolfsson and McAfee published a study in the Harvard Business Review on the role of IT in competitive advantage, entitled “Investing in the IT That Makes a Competitive Difference.” Their study confirmed that IT can play a role in competitive advantage, if deployed wisely. In their study, they draw three conclusions [6] :
- First, the data show that IT has sharpened differences among companies instead of reducing them. This reflects the fact that while companies have always varied widely in their ability to select, adopt, and exploit innovations, technology has accelerated and amplified these differences.
- Second, good management matters: Highly qualified vendors, consultants, and IT departments might be necessary for the successful implementation of enterprise technologies themselves, but the real value comes from the process innovations that can now be delivered on those platforms. Fostering the right innovations and propagating them widely are both executive responsibilities – ones that can’t be delegated.
- Finally, the competitive shakeup brought on by IT is not nearly complete, even in the IT-intensive US economy. We expect to see these altered competitive dynamics in other countries, as well, as their IT investments grow.
Information systems can be used for competitive advantage, but they must be used strategically. Organizations must understand how they want to differentiate themselves and then use all the elements of information systems (hardware, software, data, people, and process) to accomplish that differentiation.
Summary
Information systems are integrated into all components of business today, but can they bring competitive advantage? Over the years, there have been many answers to this question. Early research could not draw any connections between IT and profitability, but later research has shown that the impact can be positive. IT is not a panacea; just purchasing and installing the latest technology will not, by itself, make a company more successful. Instead, the combination of the right technologies and good management, together, will give a company the best chance of a positive result.
Study Questions
- What is the productivity paradox?
- Summarize Carr’s argument in “Does IT Matter.”
- How is the 2008 study by Brynjolfsson and McAfee different from previous studies? How is it the same?
- What does it mean for a business to have a competitive advantage?
- What are the primary activities and support activities of the value chain?
- What has been the overall impact of the Internet on industry profitability? Who has been the true winner?
- How does EDI work?
- Give an example of a semi-structured decision and explain what inputs would be necessary to provide assistance in making the decision.
- What does a collaborative information system do?
- How can IT play a role in competitive advantage, according to the 2008 article by Brynjolfsson and McAfee?
Exercises
- Do some independent research on Nicholas Carr (the author of “IT Doesn’t Matter”) and explain his current position on the ability of IT to provide competitive advantage.
- Review the WebEx website. What features of WebEx would contribute to good collaboration? What makes WebEx a better collaboration tool than something like Skype or Google Hangouts?
- Think of a semi-structured decision that you make in your daily life and build your own DSS using a spreadsheet that would help you make that decision.
- Brynjolfsson, Erik. "The Productivity Paradox of Information Technology: Review and Assessment" Copyright © 1993, 1994 Erik Brynjolfsson, All Rights Reserved Center for Coordination Science MIT Sloan School of Management Cambridge, Massachusetts Previous version: December 1991 This Version: September 1992 Published in Communications of the ACM, December, 1993; and Japan Management Research, June, 1994 (in Japanese). ↵
- Brynjolfsson, Erik and Lorin Hitt. "Beyond the Productivity Paradox", Communications of the ACM, August 1998, Vol. 41(8): pp. 49–55. Copyright © 1998 by Association for Computing Machinery, Inc. (ACM). ↵
- Porter, Michael. "Strategy and the Internet," Harvard Business Review, Vol. 79, No. 3, March 2001. http://hbswk.hbs.edu/item/2165.html ↵
- Wiseman, C., & MacMillan, I. C. (1984). CREATING COMPETITIVE WEAPONS FROM INFORMATION SYSTEMS. Journal Of Business Strategy, 5(2), 42. ↵
- Taken from http://www.isabelhealthcare.com/home/ourmission . Accessed July 15, 2013. ↵
- McAfee, Andrew and Brynjolfsson, Erik "Investing in the IT That Makes a Competitive Difference" Harvard Business Review, (July-August, 2008) ↵


6.2: The Law of Conservation of Matter
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Learning Objectives
- Correctly define a law as it pertains to science.
- State the law of conservation of matter.
In science, a law is a general statement that explains a large number of observations. Before being accepted, a law must be verified many times under many conditions. Laws are therefore considered the highest form of scientific knowledge and are generally thought to be inviolable. Scientific laws form the core of scientific knowledge. One scientific law that provides the foundation for understanding in chemistry is the law of conservation of matter. It states that in any given system that is closed to the transfer of matter (in and out), the amount of matter in the system stays constant. A concise way of expressing this law is to say that the amount of matter in a system is conserved .
With the development of more precise ideas on elements, compounds and mixtures, scientists began to investigate how and why substances react. French chemist A. Lavoisier laid the foundation to the scientific investigation of matter by describing that substances react by following certain laws. These laws are called the laws of chemical combination. These eventually formed the basis of Dalton's Atomic Theory of Matter.
Law of Conservation of Mass
According to this law, during any physical or chemical change, the total mass of the products remains equal to the total mass of the reactants.
\[ \overbrace{\underbrace{\ce{HgO (s)}}_{\text{100 g}}}^{\text{Mercuric oxide}} \rightarrow \underbrace{\overbrace{\ce{Hg (l) }}^{\text{Mercury}}}_{\text{92.6 g}} + \underbrace{\overbrace{\ce{O2 (g)}}^{\text{Oxygen}}}_{\text{7.4 g}} \nonumber \]
Another way of stating this is, "In a chemical reaction, matter is neither created nor destroyed." The law of conservation of mass is also known as the "law of indestructibility of matter."
Example \(\PageIndex{1}\)
If heating 10 grams of \(\ce{CaCO3}\) produces 4.4 g of \(\ce{CO2}\) and 5.6 g of \(\ce{CaO}\), show that these observations are in agreement with the law of conservation of mass.
Solution
- Mass of the reactants, \(\ce{CaCO3}\) : \(10 \,g\)
- Mass of the products, \(\ce{CO2}\) and \(\ce{CaO}\): \(4.4 \,g+ 5.6\, g = 10\, g\).
Because the mass of the reactants = the mass of the products, the observations are in agreement with the law of conservation of mass.
What does this mean for chemistry? In any chemical change, one or more initial substances change into a different substance or substances. Both the initial and final substances are composed of atoms because all matter is composed of atoms. According to the law of conservation of matter, matter is neither created nor destroyed, so we must have the same number and kind of atoms after the chemical change as were present before the chemical change.
It may seem as though burning destroys matter, but the same amount, or mass, of matter still exists after a campfire as before. Figure 5.1.1 shows that when wood burns, it combines with oxygen and changes not only to ashes, but also to carbon dioxide and water vapor. The gases float off into the air, leaving behind just the ashes. Suppose we had measured the mass of the wood before it burned and the mass of the ashes after it burned. Also suppose we had been able to measure the oxygen used by the fire and the gases produced by the fire. What would we find? The total mass of matter after the fire would be the same as the total mass of matter before the fire.
Exercise \(\PageIndex{1}\)
- What is the law of conservation of matter?
- How does the law of conservation of matter apply to chemistry?
- Answer a:
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The law of conservation of matter states that in any given system that is closed to the transfer of matter, the amount of matter in the system stays constant
- Answer b:
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The law of conservation of matter says that in chemical reactions, the total mass of the products must equal the total mass of the reactants.
Key Takeaway
The amount of matter in a closed system is conserved.


15.8: Learning Activities
Learning Activities
(Answers to “Learning Activities'” can be found in the ‘”Answer Key'” at the end of the book. Answers to interactive activity elements will be provided within the element as immediate feedback.)
1. A physician has ordered nafcillin 750 mg IM q 6 h. On hand is a 2 gram vial that states: “Add 6.8 mL of sterile water to provide a total solution of 8 mL.” How many milliliters should the nurse draw up to give the patient the ordered dose?
2. What are the steps the nurse should follow if the medication is given to the wrong patient?
Check your knowledge using this flashcard activity:
Query \(\PageIndex{1}\)
Use this drag and drop activity to check your knowledge about different types of medication orders.
Query \(\PageIndex{2}\)
Query \(\PageIndex{3}\)


1.7: Exclamation Marks
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Honestly, you won’t use a lot of exclamation marks in academic writing. The exclamation mark is kind of the equivalent of yelling, and most academic writing situations don’t call for much yelling, though you may feel like yelling about some of your assignments.
However, exclamation marks do serve an important function by adding emphasis to commands or other phrases, and you may find yourself needing the exclamation mark when you write dialog for certain narrative assignments.
You can certainly see the difference between a sentence punctuated with a period and one punctuated with an exclamation mark.
examples
Watch out.
Watch out!
Zombies are coming.
Zombies are coming!
In most cases, you should be careful with exclamation marks and make sure the situation calls for them. They are generally considered pretty informal, and a particularly famous writer had this to say about them:
example
“Cut out all these exclamation points. An exclamation point is like laughing at your own joke.”
— F. Scott Fitzgerald, author of
The Great Gatsby


18.2: Periodicity
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Learning Objectives
By the end of this section, you will be able to:
- Classify elements
- Make predictions about the periodicity properties of the representative elements
We begin this section by examining the behaviors of representative metals in relation to their positions in the periodic table. The primary focus of this section will be the application of periodicity to the representative metals.
It is possible to divide elements into groups according to their electron configurations. The representative elements are elements where the s and p orbitals are filling. The transition elements are elements where the d orbitals (groups 3–11 on the periodic table) are filling, and the inner transition metals are the elements where the f orbitals are filling. The d orbitals fill with the elements in group 11; therefore, the elements in group 12 qualify as representative elements because the last electron enters an s orbital. Metals among the representative elements are the representative metals . Metallic character results from an element’s ability to lose its outer valence electrons and results in high thermal and electrical conductivity, among other physical and chemical properties. There are 20 nonradioactive representative metals in groups 1, 2, 3, 12, 13, 14, and 15 of the periodic table (the elements shaded in yellow in Figure \(\PageIndex{1}\)). The radioactive elements copernicium, flerovium, polonium, and livermorium are also metals but are beyond the scope of this chapter.
In addition to the representative metals, some of the representative elements are metalloids. A metalloid is an element that has properties that are between those of metals and nonmetals; these elements are typically semiconductors.
The remaining representative elements are nonmetals. Unlike metals , which typically form cations and ionic compounds (containing ionic bonds), nonmetals tend to form anions or molecular compounds. In general, the combination of a metal and a nonmetal produces a salt. A salt is an ionic compound consisting of cations and anions.
Most of the representative metals do not occur naturally in an uncombined state because they readily react with water and oxygen in the air. However, it is possible to isolate elemental beryllium, magnesium, zinc, cadmium, mercury, aluminum, tin, and lead from their naturally occurring minerals and use them because they react very slowly with air. Part of the reason why these elements react slowly is that these elements react with air to form a protective coating. The formation of this protective coating is passivation . The coating is a nonreactive film of oxide or some other compound. Elemental magnesium, aluminum, zinc, and tin are important in the fabrication of many familiar items, including wire, cookware, foil, and many household and personal objects. Although beryllium, cadmium, mercury, and lead are readily available, there are limitations in their use because of their toxicity.
Group 1: The Alkali Metals
The alkali metals lithium, sodium, potassium, rubidium, cesium, and francium constitute group 1 of the periodic table. Although hydrogen is in group 1 (and also in group 17), it is a nonmetal and deserves separate consideration later in this chapter. The name alkali metal is in reference to the fact that these metals and their oxides react with water to form very basic (alkaline) solutions.
The properties of the alkali metals are similar to each other as expected for elements in the same family. The alkali metals have the largest atomic radii and the lowest first ionization energy in their periods. This combination makes it very easy to remove the single electron in the outermost (valence) shell of each. The easy loss of this valence electron means that these metals readily form stable cations with a charge of 1+. Their reactivity increases with increasing atomic number due to the ease of losing the lone valence electron (decreasing ionization energy). Since oxidation is so easy, the reverse, reduction, is difficult, which explains why it is hard to isolate the elements. The solid alkali metals are very soft; lithium, shown in Figure \(\PageIndex{2}\), has the lowest density of any metal (0.5 g/cm 3 ).
The alkali metals all react vigorously with water to form hydrogen gas and a basic solution of the metal hydroxide. This means they are easier to oxidize than is hydrogen. As an example, the reaction of lithium with water is:
\[\ce{2 Li(s) + 2 H2O(l) \longrightarrow 2 LiOH(aq) + H_2(g)} \nonumber \]
Alkali metals react directly with all the nonmetals (except the noble gases) to yield binary ionic compounds containing 1+ metal ions. These metals are so reactive that it is necessary to avoid contact with both moisture and oxygen in the air. Therefore, they are stored in sealed containers under mineral oil, as shown in Figure \(\PageIndex{3}\), to prevent contact with air and moisture. The pure metals never exist free (uncombined) in nature due to their high reactivity. In addition, this high reactivity makes it necessary to prepare the metals by electrolysis of alkali metal compounds.
Unlike many other metals, the reactivity and softness of the alkali metals make these metals unsuitable for structural applications. However, there are applications where the reactivity of the alkali metals is an advantage. For example, the production of metals such as titanium and zirconium relies, in part, on the ability of sodium to reduce compounds of these metals. The manufacture of many organic compounds, including certain dyes, drugs, and perfumes, utilizes reduction by lithium or sodium.
Sodium and its compounds impart a bright yellow color to a flame, as seen in Figure \(\PageIndex{4}\). Passing an electrical discharge through sodium vapor also produces this color. In both cases, this is an example of an emission spectrum as discussed in the chapter on electronic structure. Streetlights sometime employ sodium vapor lights because the sodium vapor penetrates fog better than most other light. This is because the fog does not scatter yellow light as much as it scatters white light. The other alkali metals and their salts also impart color to a flame. Lithium creates a bright, crimson color, whereas the others create a pale, violet color.
Group 2: The Alkaline Earth Metals
The alkaline earth metals (beryllium, magnesium, calcium, strontium, barium, and radium) constitute group 2 of the periodic table. The name alkaline metal comes from the fact that the oxides of the heavier members of the group react with water to form alkaline solutions. The nuclear charge increases when going from group 1 to group 2. Because of this charge increase, the atoms of the alkaline earth metals are smaller and have higher first ionization energies than the alkali metals within the same period. The higher ionization energy makes the alkaline earth metals less reactive than the alkali metals; however, they are still very reactive elements. Their reactivity increases, as expected, with increasing size and decreasing ionization energy. In chemical reactions, these metals readily lose both valence electrons to form compounds in which they exhibit an oxidation state of 2+. Due to their high reactivity, it is common to produce the alkaline earth metals, like the alkali metals, by electrolysis. Even though the ionization energies are low, the two metals with the highest ionization energies (beryllium and magnesium) do form compounds that exhibit some covalent characters. Like the alkali metals, the heavier alkaline earth metals impart color to a flame. As in the case of the alkali metals, this is part of the emission spectrum of these elements. Calcium and strontium produce shades of red, whereas barium produces a green color.
Magnesium is a silver-white metal that is malleable and ductile at high temperatures. Passivation decreases the reactivity of magnesium metal. Upon exposure to air, a tightly adhering layer of magnesium oxycarbonate forms on the surface of the metal and inhibits further reaction. (The carbonate comes from the reaction of carbon dioxide in the atmosphere.) Magnesium is the lightest of the widely used structural metals, which is why most magnesium production is for lightweight alloys.
Magnesium (shown in Figure \(\PageIndex{5}\)), calcium, strontium, and barium react with water and air. At room temperature, barium shows the most vigorous reaction. The products of the reaction with water are hydrogen and the metal hydroxide. The formation of hydrogen gas indicates that the heavier alkaline earth metals are better reducing agents (more easily oxidized) than is hydrogen. As expected, these metals react with both acids and nonmetals to form ionic compounds. Unlike most salts of the alkali metals, many of the common salts of the alkaline earth metals are insoluble in water because of the high lattice energies of these compounds, containing a divalent metal ion.
The potent reducing power of hot magnesium is useful in preparing some metals from their oxides.  Additionally, the brilliant white light emitted by burning magnesium makes it useful in flares and fireworks.
Group 12
The elements in group 12 are transition elements; however, the last electron added is not a d electron, but an s electron. Since the last electron added is an s electron, these elements qualify as representative metals, or post-transition metals. The group 12 elements behave more like the alkaline earth metals than transition metals. Group 12 contains the four elements zinc, cadmium, mercury, and copernicium. Each of these elements has two electrons in its outer shell ( ns 2 ). When atoms of these metals form cations with a charge of 2+, where the two outer electrons are lost, they have pseudo-noble gas electron configurations. Mercury is sometimes an exception because it also exhibits an oxidation state of 1+ in compounds that contain a diatomic ion. In their elemental forms and in compounds, cadmium and mercury are both toxic.
Zinc is the most reactive in group 12, and mercury is the least reactive. (This is the reverse of the reactivity trend of the metals of groups 1 and 2, in which reactivity increases down a group. The increase in reactivity with increasing atomic number only occurs for the metals in groups 1 and 2.) The decreasing reactivity is due to the formation of ions with a pseudo-noble gas configuration and to other factors that are beyond the scope of this discussion. The chemical behaviors of zinc and cadmium are quite similar to each other but differ from that of mercury.
Zinc and cadmium have lower reduction potentials than hydrogen, and, like the alkali metals and alkaline earth metals, they will produce hydrogen gas when they react with acids. The reaction of zinc with hydrochloric acid, shown in Figure \(\PageIndex{6}\), is:
\[\ce{Zn(s) + 2 H3O^{+}(aq) + 2 Cl^{-}(aq) \longrightarrow H_2(g) + Zn^{2+}(aq) + 2 Cl^{-}(aq) + 2 H2O(l)} \nonumber \]
Zinc is a silvery metal that quickly tarnishes to a blue-gray appearance. This change in color is due to an adherent coating of a basic carbonate, Zn 2 (OH) 2 CO 3 , which passivates the metal to inhibit further corrosion. Dry cell and alkaline batteries contain a zinc anode. Brass (Cu and Zn) and some bronze (Cu, Sn, and sometimes Zn) are important zinc alloys. About half of zinc production serves to protect iron and other metals from corrosion. This protection may take the form of a sacrificial anode (also known as a galvanic anode, which is a means of providing cathodic protection for various metals) or as a thin coating on the protected metal. Galvanized steel is steel with a protective coating of zinc.
Chemistry in Everyday Life: Sacrificial Anodes
A sacrificial anode, or galvanic anode, is a means of providing cathodic protection of various metals. Cathodic protection refers to the prevention of corrosion by converting the corroding metal into a cathode. As a cathode, the metal resists corrosion, which is an oxidation process. Corrosion occurs at the sacrificial anode instead of at the cathode.
The construction of such a system begins with the attachment of a more active metal (more negative reduction potential) to the metal needing protection. Attachment may be direct or via a wire. To complete the circuit, a salt bridge is necessary. This salt bridge is often seawater or ground water. Once the circuit is complete, oxidation (corrosion) occurs at the anode and not the cathode.
The commonly used sacrificial anodes are magnesium, aluminum, and zinc. Magnesium has the most negative reduction potential of the three and serves best when the salt bridge is less efficient due to a low electrolyte concentration such as in freshwater. Zinc and aluminum work better in saltwater than does magnesium. Aluminum is lighter than zinc and has a higher capacity; however, an oxide coating may passivate the aluminum. In special cases, other materials are useful. For example, iron will protect copper.
Mercury is very different from zinc and cadmium. Mercury is the only metal that is liquid at 25 °C. Many metals dissolve in mercury, forming solutions called amalgams (see the feature on Amalgams), which are alloys of mercury with one or more other metals. Mercury, shown in Figure \(\PageIndex{7}\), is a nonreactive element that is more difficult to oxidize than hydrogen. Thus, it does not displace hydrogen from acids; however, it will react with strong oxidizing acids, such as nitric acid:
\[\begin{align*}
\ce{Hg(l) + HCl(aq) &->}~\text{no reaction} \\[4pt]
\ce{3 Hg(l) + 8 HNO_3(aq) &-> 3 Hg(NO3)2(aq) + 4 H2O(l) + 2 NO(g)}
\end{align*} \]
The clear NO initially formed quickly undergoes further oxidation to the reddish brown NO 2 .
Most mercury compounds decompose when heated. Most mercury compounds contain mercury with a 2+-oxidation state. When there is a large excess of mercury, it is possible to form compounds containing the ion. All mercury compounds are toxic, and it is necessary to exercise great care in their synthesis.
Chemistry in Everyday Life: Amalgams
An amalgam is an alloy of mercury with one or more other metals. This is similar to considering steel to be an alloy of iron with other metals. Most metals will form an amalgam with mercury, with the main exceptions being iron, platinum, tungsten, and tantalum.
Due to toxicity issues with mercury, there has been a significant decrease in the use of amalgams. Historically, amalgams were important in electrolytic cells and in the extraction of gold. Amalgams of the alkali metals still find use because they are strong reducing agents and easier to handle than the pure alkali metals.
Prospectors had a problem when they found finely divided gold. They learned that adding mercury to their pans collected the gold into the mercury to form an amalgam for easier collection. Unfortunately, losses of small amounts of mercury over the years left many streams in California polluted with mercury.
Dentists use amalgams containing silver and other metals to fill cavities. There are several reasons to use an amalgam including low cost, ease of manipulation, and longevity compared to alternate materials. Dental amalgams are approximately 50% mercury by weight, which, in recent years, has become a concern due to the toxicity of mercury.
After reviewing the best available data, the Food and Drug Administration (FDA) considers amalgam-based fillings to be safe for adults and children over six years of age. Even with multiple fillings, the mercury levels in the patients remain far below the lowest levels associated with harm. Clinical studies have found no link between dental amalgams and health problems. Health issues may not be the same in cases of children under six or pregnant women. The FDA conclusions are in line with the opinions of the Environmental Protection Agency (EPA) and Centers for Disease Control (CDC). The only health consideration noted is that some people are allergic to the amalgam or one of its components.
Group 13
Group 13 contains the metalloid boron and the metals aluminum, gallium, indium, and thallium. The lightest element, boron, is semiconducting, and its binary compounds tend to be covalent and not ionic. The remaining elements of the group are metals, but their oxides and hydroxides change characters. The oxides and hydroxides of aluminum and gallium exhibit both acidic and basic behaviors. A substance, such as these two, that will react with both acids and bases is amphoteric. This characteristic illustrates the combination of nonmetallic and metallic behaviors of these two elements. Indium and thallium oxides and hydroxides exhibit only basic behavior, in accordance with the clearly metallic character of these two elements. The melting point of gallium is unusually low (about 30 °C) and will melt in your hand.
Aluminum is amphoteric because it will react with both acids and bases. A typical reaction with an acid is:
\[\ce{2 Al(s) + 6 HCl(aq) \longrightarrow 2 AlCl_3(aq) + 3 H_2(g)} \nonumber \]
The products of the reaction of aluminum with a base depend upon the reaction conditions, with the following being one possibility:
\[\ce{2 Al(s) + 2 NaOH(aq) + 6 H2O(l) -> 2 Na[Al(OH)4](aq) + 3 H2(g)} \nonumber \]
With both acids and bases, the reaction with aluminum generates hydrogen gas.
The group 13 elements have a valence shell electron configuration of ns 2 np 1 . Aluminum normally uses all of its valence electrons when it reacts, giving compounds in which it has an oxidation state of 3+. Although many of these compounds are covalent, others, such as AlF 3 and Al 2 (SO 4 ) 3 , are ionic. Aqueous solutions of aluminum salts contain the cation \(\ce{[Al(H2O)6]^{3+}}\) abbreviated as Al 3 + ( aq ). Gallium, indium, and thallium also form ionic compounds containing M 3+ ions. These three elements exhibit not only the expected oxidation state of 3+ from the three valence electrons but also an oxidation state (in this case, 1+) that is two below the expected value. This phenomenon, the inert pair effect, refers to the formation of a stable ion with an oxidation state two lower than expected for the group. The pair of electrons is the valence s orbital for those elements. In general, the inert pair effect is important for the lower p -block elements. In an aqueous solution, the Tl + ( aq ) ion is more stable than is Tl 3 + ( aq ). In general, these metals will react with air and water to form 3+ ions; however, thallium reacts to give thallium(I) derivatives. The metals of group 13 all react directly with nonmetals such as sulfur, phosphorus, and the halogens, forming binary compounds.
The metals of group 13 (Al, Ga, In, and Tl) are all reactive. However, passivation occurs as a tough, hard, thin film of the metal oxide forms upon exposure to air. Disruption of this film may counter the passivation, allowing the metal to react. One way to disrupt the film is to expose the passivated metal to mercury. Some of the metal dissolves in the mercury to form an amalgam, which sheds the protective oxide layer to expose the metal to further reaction. The formation of an amalgam allows the metal to react with air and water.
Link to Learning
Although easily oxidized, the passivation of aluminum makes it very useful as a strong, lightweight building material. Because of the formation of an amalgam, mercury is corrosive to structural materials made of aluminum. This video demonstrates how the integrity of an aluminum beam can be destroyed by the addition of a small amount of elemental mercury.
The most important uses of aluminum are in the construction and transportation industries, and in the manufacture of aluminum cans and aluminum foil. These uses depend on the lightness, toughness, and strength of the metal, as well as its resistance to corrosion. Because aluminum is an excellent conductor of heat and resists corrosion, it is useful in the manufacture of cooking utensils.
Aluminum is a very good reducing agent and may replace other reducing agents in the isolation of certain metals from their oxides. Although more expensive than reduction by carbon, aluminum is important in the isolation of Mo, W, and Cr from their oxides.
Group 14
The metallic members of group 14 are tin, lead, and flerovium. Carbon is a typical nonmetal. The remaining elements of the group, silicon and germanium, are examples of semimetals or metalloids. Tin and lead form the stable divalent cations, Sn 2 + and Pb 2 + , with oxidation states two below the group oxidation state of 4+. The stability of this oxidation state is a consequence of the inert pair effect. Tin and lead also form covalent compounds with a formal 4+-oxidation state. For example, SnCl 4 and PbCl 4 are low-boiling covalent liquids.
Tin reacts readily with nonmetals and acids to form tin(II) compounds (indicating that it is more easily oxidized than hydrogen) and with nonmetals to form either tin(II) or tin(IV) compounds (shown in Figure \(\PageIndex{8}\)), depending on the stoichiometry and reaction conditions. Lead is less reactive. It is only slightly easier to oxidize than hydrogen, and oxidation normally requires a hot concentrated acid.
Many of these elements exist as allotropes. Allotropes are two or more forms of the same element in the same physical state with different chemical and physical properties. There are two common allotropes of tin. These allotropes are grey (brittle) tin and white tin. As with other allotropes, the difference between these forms of tin is in the arrangement of the atoms. White tin is stable above 13.2 °C and is malleable like other metals. At low temperatures, gray tin is the more stable form. Gray tin is brittle and tends to break down to a powder. Consequently, articles made of tin will disintegrate in cold weather, particularly if the cold spell is lengthy. The change progresses slowly from the spot of origin, and the gray tin that is first formed catalyzes further change. In a way, this effect is similar to the spread of an infection in a plant or animal body, leading people to call this process tin disease or tin pest.
The principal use of tin is in the coating of steel to form tin plate-sheet iron, which constitutes the tin in tin cans. Important tin alloys are bronze (Cu and Sn) and solder (Sn and Pb). Lead is important in the lead storage batteries in automobiles.
Group 15
Bismuth , the heaviest member of group 15, is a less reactive metal than the other representative metals. It readily gives up three of its five valence electrons to active nonmetals to form the tri-positive ion, Bi 3 + . It forms compounds with the group oxidation state of 5+ only when treated with strong oxidizing agents. The stability of the 3+-oxidation state is another example of the inert pair effect.


3.13: F(000)
The expression for a structure factor evaluated in the zeroth-order case h = k = l = 0 yields the result
where f r is the real part of the scattering factors at \(\theta = 0^\circ\), f i is the imaginary part of the scattering factors at \(\theta = 0^\circ\), θ is the Bragg angle, and the sum is taken over each atom in the unit cell.
F (000) is computed without dispersion effects in electron-density calculation by Fourier inversion. In all cases, non-dispersive F (000) is a structure factor and not a structure amplitude: it has both magnitude and a sign.
For X-rays non-dispersive F (000) is positive definite and in many cases an integer (but it is not an integer for non-stoichiometric compounds). It counts the number of electrons in the cell.
For neutrons non-dispersive F (000) is either positive or negative and counts the total nuclear scattering power in the cell.


7.5: Glycolysis - The Energy-Requiring Steps of Glycolysis
- Outline the energy-requiring steps of glycolysis
First Half of Glycolysis (Energy-Requiring Steps)
In the first half of glycolysis, two adenosine triphosphate (ATP) molecules are used in the phosphorylation of glucose, which is then split into two three-carbon molecules as described in the following steps.
Step 1. The first step in glycolysis is catalyzed by hexokinase, an enzyme with broad specificity that catalyzes the phosphorylation of six-carbon sugars. Hexokinase phosphorylates glucose using ATP as the source of the phosphate, producing glucose-6-phosphate, a more reactive form of glucose. This reaction prevents the phosphorylated glucose molecule from continuing to interact with the GLUT proteins. It can no longer leave the cell because the negatively-charged phosphate will not allow it to cross the hydrophobic interior of the plasma membrane.
Step 2. In the second step of glycolysis, an isomerase converts glucose-6-phosphate into one of its isomers, fructose-6-phosphate. An enzyme that catalyzes the conversion of a molecule into one of its isomers is an isomerase. (This change from phosphoglucose to phosphofructose allows the eventual split of the sugar into two three-carbon molecules).
Step 3. The third step is the phosphorylation of fructose-6-phosphate, catalyzed by the enzyme phosphofructokinase. A second ATP molecule donates a high-energy phosphate to fructose-6-phosphate, producing fructose-1,6-bisphosphate. In this pathway, phosphofructokinase is a rate-limiting enzyme. It is active when the concentration of ADP is high; it is less active when ADP levels are low and the concentration of ATP is high. Thus, if there is “sufficient” ATP in the system, the pathway slows down. This is a type of end-product inhibition, since ATP is the end product of glucose catabolism.
Step 4. The newly-added high-energy phosphates further destabilize fructose-1,6-bisphosphate. The fourth step in glycolysis employs an enzyme, aldolase, to cleave 1,6-bisphosphate into two three-carbon isomers: dihydroxyacetone-phosphate and glyceraldehyde-3-phosphate.
Step 5. In the fifth step, an isomerase transforms the dihydroxyacetone-phosphate into its isomer, glyceraldehyde-3-phosphate. Thus, the pathway will continue with two molecules of a single isomer. At this point in the pathway, there is a net investment of energy from two ATP molecules in the breakdown of one glucose molecule.
Key Points
- ATP molecules donate high energy phosphate groups during the two phosphorylation steps, step 1 with hexokinase and step 3 with phosphofructokinase, in the first half of glycolysis.
- In steps 2 and 5, isomerases convert molecules into their isomers to allow glucose to be split eventually into two molecules of glyceraldehyde-3-phosphate, which continues into the second half of glycolysis.
- The enzyme aldolase in step 4 of glycolysis cleaves the six-carbon sugar 1,6-bisphosphate into two three-carbon sugar isomers, dihydroxyacetone-phosphate and glyceraldehyde-3-phosphate.
Key Terms
- glucose : a simple monosaccharide (sugar) with a molecular formula of C6H12O6; it is a principal source of energy for cellular metabolism
- adenosine triphosphate : a multifunctional nucleoside triphosphate used in cells as a coenzyme, often called the “molecular unit of energy currency” in intracellular energy transfer