16.5: Batteries and Fuel Cells
- Classify batteries as primary or secondary
- List some of the characteristics and limitations of batteries
- Provide a general description of a fuel cell
A battery is an electrochemical cell or series of cells that produces an electric current. In principle, any galvanic cell could be used as a battery. An ideal battery would never run down, produce an unchanging voltage, and be capable of withstanding environmental extremes of heat and humidity. Real batteries strike a balance between ideal characteristics and practical limitations. For example, the mass of a car battery is about 18 kg or about 1% of the mass of an average car or light-duty truck. This type of battery would supply nearly unlimited energy if used in a smartphone, but would be rejected for this application because of its mass. Thus, no single battery is “best” and batteries are selected for a particular application, keeping things like the mass of the battery, its cost, reliability, and current capacity in mind. There are two basic types of batteries: primary and secondary. A few batteries of each type are described next.
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Primary Batteries
Primary batteries are single-use batteries because they cannot be recharged. A common primary battery is the dry cell (Figure \(\PageIndex{1}\)). The dry cell is a zinc-carbon battery. The zinc can serves as both a container and the negative electrode. The positive electrode is a rod made of carbon that is surrounded by a paste of manganese(IV) oxide, zinc chloride, ammonium chloride, carbon powder, and a small amount of water. The reaction at the anode can be represented as the ordinary oxidation of zinc:
\[\ce{Zn}(s)⟶\ce{Zn^2+}(aq)+\ce{2e-} \hspace{20px} E^\circ_{\ce{Zn^2+/Zn}}=\mathrm{−0.7618\: V} \nonumber \]
The reaction at the cathode is more complicated, in part because more than one reaction occurs. The series of reactions that occurs at the cathode is approximately
\[\ce{2MnO2}(s)+\ce{2NH4Cl}(aq)+\ce{2e-}⟶\ce{Mn2O3}(s)+\ce{2NH3}(aq)+\ce{H2O}(l)+\ce{2Cl-} \nonumber \]
The overall reaction for the zinc–carbon battery can be represented as
\[\ce{2MnO2}(s) + \ce{2NH4Cl}(aq) + \ce{Zn}(s) ⟶ \ce{Zn^2+}(aq) + \ce{Mn2O3}(s) + \ce{2NH3}(aq) + \ce{H2O}(l) + \ce{2Cl-} \nonumber \]
with an overall cell potential which is initially about 1.5 V, but decreases as the battery is used. It is important to remember that the voltage delivered by a battery is the same regardless of the size of a battery. For this reason, D, C, A, AA , and AAA batteries all have the same voltage rating. However, larger batteries can deliver more moles of electrons. As the zinc container oxidizes, its contents eventually leak out, so this type of battery should not be left in any electrical device for extended periods.
Alkaline batteries (Figure \(\PageIndex{2}\)) were developed in the 1950s partly to address some of the performance issues with zinc–carbon dry cells. They are manufactured to be exact replacements for zinc-carbon dry cells. As their name suggests, these types of batteries use alkaline electrolytes, often potassium hydroxide. The reactions are
\[\begin{align*} &\textrm{anode: }\ce{Zn}(s)+\ce{2OH-}(aq)⟶\ce{ZnO}(s)+\ce{H2O}(l)+\ce{2e-} \hspace{40px} E^\circ_\ce{anode}=\mathrm{−1.28\: V}\\ &\underline{\textrm{cathode: }\ce{2MnO2}(s)+\ce{H2O}(l)+\ce{2e-}⟶\ce{Mn2O3}(s)+\ce{2OH-}(aq) \hspace{40px} E^\circ_\ce{cathode}=\mathrm{+0.15\: V}}\\ &\textrm{overall: }\ce{Zn}(s)+\ce{2MnO2}(s)⟶\ce{ZnO}(s)+\ce{Mn2O3}(s) \hspace{40px} E^\circ_\ce{cell}=\mathrm{+1.43\: V} \end{align*} \nonumber \]
An alkaline battery can deliver about three to five times the energy of a zinc-carbon dry cell of similar size. Alkaline batteries are prone to leaking potassium hydroxide, so these should also be removed from devices for long-term storage. While some alkaline batteries are rechargeable, most are not. Attempts to recharge an alkaline battery that is not rechargeable often leads to rupture of the battery and leakage of the potassium hydroxide electrolyte.
Secondary Batteries
Secondary batteries are rechargeable. These are the types of batteries found in devices such as smartphones, electronic tablets, and automobiles.
Nickel-cadmium, or NiCd, batteries (Figure \(\PageIndex{3}\)) consist of a nickel-plated cathode, cadmium-plated anode, and a potassium hydroxide electrode. The positive and negative plates, which are prevented from shorting by the separator, are rolled together and put into the case. This is a “jelly-roll” design and allows the NiCd cell to deliver much more current than a similar-sized alkaline battery. The reactions are
\[\begin{align*}
&\textrm{anode: }\ce{Cd}(s)+\ce{2OH-}(aq)⟶\ce{Cd(OH)2}(s)+\ce{2e-}\\
&\underline{\textrm{cathode: }\ce{NiO2}(s)+\ce{2H2O}(l)+\ce{2e-}⟶\ce{Ni(OH)2}(s)+\ce{2OH-}(aq)}\\
&\textrm{overall: }\ce{Cd}(s)+\ce{NiO2}(s)+\ce{2H2O}(l)⟶\ce{Cd(OH)2}(s)+\ce{Ni(OH)2}(s) \end{align*} \nonumber \]
The voltage is about 1.2 V to 1.25 V as the battery discharges. When properly treated, a NiCd battery can be recharged about 1000 times. Cadmium is a toxic heavy metal so NiCd batteries should never be opened or put into the regular trash.
Lithium ion batteries (Figure \(\PageIndex{4}\)) are among the most popular rechargeable batteries and are used in many portable electronic devices. The reactions are
\[\begin{align*} &\textrm{anode: }\ce{LiCoO2}⇌\ce{Li}_{1-x}\ce{CoO2}+x\ce{Li+}+x\ce{e-}\\ &\textrm{cathode: }x\ce{Li+}+x\ce{e-}+x\ce{C6}⇌x\ce{LiC6}\\ &\overline{\textrm{overall: }\ce{LiCoO2}+x\ce{C6}⇌\ce{Li}_{1-x}\ce{CoO2}+x\ce{LiC6}} \end{align*} \nonumber \]
With the coefficients representing moles, x is no more than about 0.5 moles. The battery voltage is about 3.7 V. Lithium batteries are popular because they can provide a large amount current, are lighter than comparable batteries of other types, produce a nearly constant voltage as they discharge, and only slowly lose their charge when stored.
The lead acid battery (Figure \(\PageIndex{5}\)) is the type of secondary battery used in your automobile. It is inexpensive and capable of producing the high current required by automobile starter motors. The reactions for a lead acid battery are
\[\begin{align*} &\textrm{anode: }\ce{Pb}(s)+\ce{HSO4-}(aq)⟶\ce{PbSO4}(s)+\ce{H+}(aq)+\ce{2e-}\\ &\underline{\textrm{cathode: } \ce{PbO2}(s)+\ce{HSO4-}(aq)+\ce{3H+}(aq)+\ce{2e-}⟶\ce{PbSO4}(s)+\ce{2H2O}(l)}\\ &\textrm{overall: }\ce{Pb}(s)+\ce{PbO2}(s)+\ce{2H2SO4}(aq)⟶\ce{2PbSO4}(s)+\ce{2H2O}(l) \end{align*} \nonumber \]
Each cell produces 2 V, so six cells are connected in series to produce a 12-V car battery. Lead acid batteries are heavy and contain a caustic liquid electrolyte, but are often still the battery of choice because of their high current density. Since these batteries contain a significant amount of lead, they must always be disposed of properly.
Fuel Cells
A fuel cell is a device that converts chemical energy into electrical energy. Fuel cells are similar to batteries but require a continuous source of fuel, often hydrogen. They will continue to produce electricity as long as fuel is available. Hydrogen fuel cells have been used to supply power for satellites, space capsules, automobiles, boats, and submarines (Figure \(\PageIndex{6}\)).
In a hydrogen fuel cell, the reactions are
\[\begin{align*}
&\textrm{anode: }\ce{2H2 + 2O^2- ⟶ 2H2O + 4e-}\\
&\underline{\textrm{cathode: }\ce{O2 + 4e- ⟶ 2O^2-}\hspace{55px}}\\
&\textrm{overall: }\ce{2H2 + O2 ⟶ 2H2O} \end{align*} \nonumber \]
The voltage is about 0.9 V. The efficiency of fuel cells is typically about 40% to 60%, which is higher than the typical internal combustion engine (25% to 35%) and, in the case of the hydrogen fuel cell, produces only water as exhaust. Currently, fuel cells are rather expensive and contain features that cause them to fail after a relatively short time.
Summary
Batteries are galvanic cells, or a series of cells, that produce an electric current. When cells are combined into batteries, the potential of the battery is an integer multiple of the potential of a single cell. There are two basic types of batteries: primary and secondary. Primary batteries are “single use” and cannot be recharged. Dry cells and (most) alkaline batteries are examples of primary batteries. The second type is rechargeable and is called a secondary battery. Examples of secondary batteries include nickel-cadmium (NiCd), lead acid, and lithium ion batteries. Fuel cells are similar to batteries in that they generate an electrical current, but require continuous addition of fuel and oxidizer. The hydrogen fuel cell uses hydrogen and oxygen from the air to produce water, and is generally more efficient than internal combustion engines.
Summary
- alkaline battery
- primary battery that uses an alkaline (often potassium hydroxide) electrolyte; designed to be an exact replacement for the dry cell, but with more energy storage and less electrolyte leakage than typical dry cell
- battery
- galvanic cell or series of cells that produces a current; in theory, any galvanic cell
- dry cell
- primary battery, also called a zinc-carbon battery; can be used in any orientation because it uses a paste as the electrolyte; tends to leak electrolyte when stored
- fuel cell
- devices that produce an electrical current as long as fuel and oxidizer are continuously added; more efficient than internal combustion engines
- lead acid battery
- secondary battery that consists of multiple cells; the lead acid battery found in automobiles has six cells and a voltage of 12 V
- lithium ion battery
- very popular secondary battery; uses lithium ions to conduct current and is light, rechargeable, and produces a nearly constant potential as it discharges
- nickel-cadmium battery
- (NiCd battery) secondary battery that uses cadmium, which is a toxic heavy metal; heavier than lithium ion batteries, but with similar performance characteristics
- primary battery
- single-use nonrechargeable battery
- secondary battery
- battery that can be recharged


18.1: Complex numbers
Informally, a complex number is a number that can be put in the form
\[z=x+i\cdot y, \]
where \(x\) and \(y\) are real numbers and \(i^2=-1\) .
The set of complex numbers will be further denoted by \(\mathbb{C}\) . If \(x\) , \(y\) , and \(z\) are as in 18.1.1, then \(x\) is called the real part and \(y\) the imaginary part of the complex number \(z\) .
On the more formal level, a complex number is a pair of real numbers \((x,y)\) with the addition and multiplication described below; the expression \(x + i\cdot y\) is only a convenient way to write the pair \((x,y)\) .
\[\begin{aligned} (x_1+i\cdot y_1) + (x_2+i\cdot y_2) &:= (x_1+x_2) + i\cdot(y_1+y_2); \\ (x_1+i\cdot y_1)\cdot(x_2+i\cdot y_2) &:= (x_1\cdot x_2-y_1\cdot y_2) + i\cdot(x_1\cdot y_2+y_1\cdot x_2). \end{aligned}\]


12.1.6: Social Media and Web 2.0
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Learning Objectives
- Identify the major social networking sites, and give possible uses and demographics for each one.
- Show the positive and negative effects of blogs on the distribution and creation of information.
- Explain the ways privacy has been addressed on the Internet.
- Identify new information that marketers can use because of social networking.
Although GeoCities lost market share, and although theGlobe.com never really made it to the 21st century, social networking has persisted. There are many different types of social media available today, from social networking sites like Facebook to blogging services like Blogger and WordPress.com . All these sites bring something different to the table, and a few of them even try to bring just about everything to the table at once.
Social Networking
Social networking services—like Facebook, Twitter, LinkedIn, Google Buzz, and MySpace—provide a limited but public platform for users to create a “profile.” This can range anywhere from the 140-character (that’s letters and spaces, not words) “tweets” on Twitter, to the highly customizable MySpace, which allows users to blog, customize color schemes, add background images, and play music. Each of these services has its key demographic—MySpace, for example, is particularly geared toward younger users. Its huge array of features made it attractive to this demographic at first, but eventually it was overrun with corporate marketing and solicitations for pornographic websites, leading many users to abandon the service. In addition, competing social networking sites like Facebook offer superior interfaces that have lured away many of MySpace’s users. MySpace has attempted to catch up by upgrading its own interface, but it now faces the almost insurmountable obstacle of already-satisfied users of competing social networking services. As Internet technology evolves rapidly, most users have few qualms about moving to whichever site offers the better experience; most users have profiles and accounts on many services at once. But as relational networks become more and more established and concentrated on a few social media sites, it becomes increasingly difficult for newcomers and lagging challengers to offer the same rich networking experience. For a Facebook user with hundreds of friends in his or her social network, switching to MySpace and bringing along his or her entire network of friends is a daunting and infeasible prospect. Google has attempted to circumvent the problem of luring users to create new social networks by building its Buzz service into its popular Gmail, ensuring that Buzz has a built-in user base and lowering the social costs of joining a new social network by leveraging users’ Gmail contact lists. It remains to be seen if Google will be truly successful in establishing a vital new social networking service, but its tactic of integrating Buzz into Gmail underscores how difficult it has become to compete with established social networks like Twitter and Facebook.
Whereas MySpace initially catered to a younger demographic, LinkedIn caters to business professionals looking for networking opportunities. LinkedIn is free to join and allows users to post resumes and job qualifications (rather than astrological signs and favorite television shows). Its tagline, “Relationships matter,” emphasizes the role of an increasingly networked world in business; just as a musician might use MySpace to promote a new band, a LinkedIn user can use the site to promote professional services. While these two sites have basically the same structure, they fulfill different purposes for different social groups; the character of social networking is highly dependent on the type of social circle.
Twitter offers a different approach to social networking, allowing users to “tweet” 140-character messages to their “followers,” making it something of a hybrid of instant messaging and blogging. Twitter is openly searchable, meaning that anyone can visit the site and quickly find out what other Twitter users are saying about any subject. Twitter has proved useful for journalists reporting on breaking news, as well as highlighting the “best of” the Internet. Twitter has also been useful for marketers looking for a free public forum to disseminate marketing messages. It became profitable in December 2009 through a $25 million deal allowing Google and Microsoft to display its users’ 140-character messages in their search results.Eliot Van Buskirk, “Twitter Earns First Profit Selling Search to Google, Microsoft,” Wired , December 21, 2009, http://www.wired.com/epicenter/2009/12/twitter-earns-first-profit-selling-search-to-google-microsoft . Facebook, originally deployed exclusively to Ivy League schools, has since opened its doors to anyone over 13 with an email account. With the explosion of the service and its huge growth among older demographics, “My parents joined Facebook” has become a common complaint.See the blog at http://myparentsjoinedfacebook.com/ for examples on the subject.
Another category of social media, blogs began as an online, public version of a diary or journal. Short for “web logs,” these personal sites give anyone a platform to write about anything they want to. Posting tweets on the Twitter service is considered micro-blogging (because of the extremely short length of the posts). Some services, like LiveJournal, highlight their ability to provide up-to-date reports on personal feelings, even going so far as to add a “mood” shorthand at the end of every post. The Blogger service (now owned by Google) allows users with Google accounts to follow friends’ blogs and post comments. WordPress.com , the company that created the open-source blogging platform WordPress.org, and LiveJournal both follow the freemium model by allowing a basic selection of settings for free, with the option to pay for things like custom styles and photo hosting space. What these all have in common, however, is their bundling of social networking (such as the ability to easily link to and comment on friends’ blogs) with an expanded platform for self-expression. At this point, most traditional media companies have incorporated blogs, Twitter, and other social media as a way to allow their reporters to update instantly and often. This form of media convergence, discussed in detail in Section 11.3 of this chapter, is now a necessary part of doing business.
There are many other types of social media out there, many of which can be called to mind with a single name: YouTube (video sharing), Wikipedia (open-source encyclopedia composed of “wikis” editable by any user), Flickr (photo sharing), and Digg (content sharing). Traditional media outlets have begun referring to these social media services and others like them as “Web 2.0.” Web 2.0 is not a new version of the web; rather, the term is a reference to the increased focus on user-generated content and social interaction on the web, as well as the evolution of online tools to facilitate that focus. Instead of relying on professional reporters to get information about a protest in Iran, a person could just search for “Iran” on Twitter and likely end up with hundreds of tweets linking to everything from blogs to CNN.com to YouTube videos from Iranian citizens themselves. In addition, many of these tweets may actually be instant updates from people using Twitter in Iran. This allows people to receive information straight from the source, without being filtered through news organizations or censored by governments.
Going Viral
In 2009, Susan Boyle, an unemployed middle-aged Scottish woman, appeared on Britain’s Got Talent and sang “I Dreamed a Dream” from the musical Les Misérables , becoming an international star almost overnight. It was not her performance itself that catapulted her to fame and sent her subsequently released album to the top of the UK Billboard charts and kept it there for 6 weeks. What did it was a YouTube video of her performance, viewed by 87,000,000 people and counting.BritainsSoTalented, “Susan Boyle - Singer - Britains Got Talent 2009,” 2009, http://www.youtube.com/watch?v=9lp0IWv8QZY .
Media that is spread from person to person when, for example, a friend sends you a link saying “You’ve got to see this!” is said to have “gone viral.” Marketing and advertising agencies have deemed advertising that makes use of this phenomenon as “viral marketing.” Yet many YouTube sensations have not come from large marketing firms. For instance, the four-piece pop-punk band OK Go filmed a music video on a tiny budget for their song “Here It Goes Again” and released it exclusively on YouTube in 2006. Featuring a choreographed dance done on eight separate treadmills, the video quickly became a viral sensation and, as of May 2011, has over 7,265,825 views. The video helped OK Go attract millions of new fans and earned them a Grammy award in 2007, making it one of the most notable successes of viral Internet marketing. Viral marketing is, however, notoriously unpredictable and is liable to spawn remixes, spin-offs, and spoofs that can dilute or damage the messages that marketers intend to spread. Yet, when it is successful, viral marketing can reach millions of people for very little money and can even make it into the mainstream news.
Recent successes and failures in viral marketing demonstrate how difficult it is for marketers to control their message as it is unleashed virally. In 2007, the band Radiohead released their album In Rainbows online, allowing fans to download it for any amount of money they chose—including for free. Despite practically giving the album away, the digital release of In Rainbows still pulled in more money than Radiohead’s previous album, Hail to the Thief , while the band simultaneously sold a huge number of $80 collector editions and still sold physical CDs months after the digital release became available. New Musical Express , “Radiohead Reveal How Successful ‘In Rainbows’ Download Really Was,” October 15, 2008, http://www.nme.com/news/radiohead/40444 . In contrast, the food giant Healthy Choice enlisted Classymommy.com blogger Colleen Padilla to write a sponsored review of its product, leading to a featured New York Times article on the blogger (not the product), which gave the product only a passing mention.Pradnya Joshi, “Approval by a Blogger May Please a Sponsor,” New York Times , July 12, 2009, http://www.nytimes.com/2009/07/13/technology/internet/13blog.html . Often, a successfully marketed product will reach some people through the Internet and then break through into the mainstream media. Yet as the article about Padilla shows, sometimes the person writing about the product overshadows the product itself.
Not all viral media is marketing, however. In 2007, someone posted a link to a new trailer for Grand Theft Auto IV on the video games message board of the web forum 4chan.org. When users followed the link, they were greeted not with a video game trailer but with Rick Astley singing his 1987 hit “Never Gonna Give You Up.” This technique—redirecting someone to that particular music video—became known as Rickrolling and quickly became one of the most well-known Internet memes of all time. Fox News , “The Biggest Little Internet Hoax on Wheels Hits Mainstream,” April 22, 2008, www.foxnews.com/story/0,2933,352010,00.html. An Internet meme is a concept that quickly replicates itself throughout the Internet, and it is often nonsensical and absurd. Another meme, “Lolcats,” consists of misspelled captions—“I can has cheezburger?” is a classic example—over pictures of cats. Often, these memes take on a metatextual quality, such as the meme “Milhouse is not a meme,” in which the character Milhouse (from the television show The Simpsons ) is told that he is not a meme. Chronicling memes is notoriously difficult, because they typically spring into existence seemingly overnight, propagate rapidly, and disappear before ever making it onto the radar of mainstream media—or even the mainstream Internet user.
Benefits and Problems of Social Media
Social media allows an unprecedented volume of personal, informal communication in real time from anywhere in the world. It allows users to keep in touch with friends on other continents, yet keeps the conversation as casual as a Facebook wall post. In addition, blogs allow us to gauge a wide variety of opinions and have given “breaking news” a whole new meaning. Now, news can be distributed through many major outlets almost instantaneously, and different perspectives on any one event can be aired concurrently. In addition, news organizations can harness bloggers as sources of real-time news, in effect outsourcing some of their news-gathering efforts to bystanders on the scene. This practice of harnessing the efforts of several individuals online to solve a problem is known as crowdsourcing.
The downside of the seemingly infinite breadth of online information is that there is often not much depth to the coverage of any given topic. The superficiality of information on the Internet is a common gripe among many journalists who are now rushed to file news reports several times a day in an effort to complete with the “blogosphere,” or the crowd of bloggers who post both original news stories and aggregate previously published news from other sources. Whereas traditional print organizations at least had the “luxury” of the daily print deadline, now journalists are expected to blog or tweet every story and file reports with little or no analysis, often without adequate time to confirm the reliability of their sources.Ken Auletta, “Non-Stop News,” Annals of Communications, New Yorker , January 25, 2010, http://www.newyorker.com/reporting/2010/01/25/100125fa_fact_auletta .
Additionally, news aggregators like Google News profit from linking to journalists’ stories at major newspapers and selling advertising, but these profits are not shared with the news organizations and journalists who created the stories. It is often difficult for journalists to keep up with the immediacy of the nonstop news cycle, and with revenues for their efforts being diverted to news aggregators, journalists and news organizations increasingly lack the resources to keep up this fast pace. Twitter presents a similar problem: Instead of getting news from a specific newspaper, many people simply read the articles that are linked from a Twitter feed. As a result, the news cycle leaves journalists no time for analysis or cross-examination. Increasingly, they will simply report, for example, on what a politician or public relations representative says without following up on these comments or fact-checking them. This further shortens the news cycle and makes it much easier for journalists to be exploited as the mouthpieces of propaganda.
Consequently, the very presence of blogs and their seeming importance even among mainstream media has made some critics wary. Internet entrepreneur Andrew Keen is one of these people, and his book The Cult of the Amateur follows up on the famous thought experiment suggesting that infinite monkeys, given infinite typewriters, will one day randomly produce a great work of literature:Proposed by T. H. Huxley (the father of Aldous Huxley), this thought experiment suggests that infinite monkeys given infinite typewriters would, given infinite time, eventually write Hamlet .  Keen also suggests that the Internet is really just a case of my-word-against-yours, where bloggers are not required to back up their arguments with credible sources. “These days, kids can’t tell the difference between credible news by objective professional journalists and what they read on [a random website].”Andrew Keen, The Cult of the Amateur: How Today’s Internet Is Killing Our Culture (New York: Doubleday, 2007). Follow Keen on Twitter: twitter.com/ajkeen. Commentators like Keen worry that this trend will lead to young people’s inability to distinguish credible information from a mass of sources, eventually leading to a sharp decrease in credible sources of information.
For defenders of the Internet, this argument seems a bit overwrought: “A legitimate interest in the possible effects of significant technological change in our daily lives can inadvertently dovetail seamlessly into a ‘kids these days’ curmudgeonly sense of generational degeneration, which is hardly new.”Greg Downey, “Is Facebook Rotting Our Children’s Brains?” Neuroanthropology.net , March 2, 2009, http://neuroanthropology.net/2009/03/02/is-facebook-rotting-our-childrens-brains/ . Greg Downey, who runs the collaborative blog Neuroanthropology, says that fear of kids on the Internet—and on social media in particular—can slip into “a ‘one-paranoia-fits-all’ approach to technological change.” For the argument that online experiences are “devoid of cohesive narrative and long-term significance,” Downey offers that, on the contrary, “far from evacuating narrative, some social networking sites might be said to cause users to ‘narrativize’ their experience, engaging with everyday life already with an eye toward how they will represent it on their personal pages.”
Another argument in favor of social media defies the warning that time spent on social networking sites is destroying the social skills of young people. “The debasement of the word ‘friend’ by [Facebook’s] use of it should not make us assume that users can’t tell the difference between friends and Facebook ‘friends,’” writes Downey. On the contrary, social networks (like the Usenet of the past) can even provide a place for people with more obscure interests to meet one another and share commonalities. In addition, marketing through social media is completely free—making it a valuable tool for small businesses with tight marketing budgets. A community theater can invite all of its “fans” to a new play for less money than putting an ad in the newspaper, and this direct invitation is far more personal and specific. Many people see services like Twitter, with its “followers,” as more semantically appropriate than the “friends” found on Facebook and MySpace, and because of this Twitter has, in many ways, changed yet again the way social media is conceived. Rather than connecting with “friends,” Twitter allows social media to be purely a source of information, thereby making it far more appealing to adults. In addition, while 140 characters may seem like a constraint to some, it can be remarkably useful to the time-strapped user looking to catch up on recent news.
Social media’s detractors also point to the sheer banality of much of the conversation on the Internet. Again, Downey keeps this in perspective: “The banality of most conversation is also pretty frustrating,” he says. Downey suggests that many of the young people using social networking tools see them as just another aspect of communication. However, Downey warns that online bullying has the potential to pervade larger social networks while shielding perpetrators through anonymity.
Another downside of many of the Internet’s segmented communities is that users tend to be exposed only to information they are interested in and opinions they agree with. This lack of exposure to novel ideas and contrary opinions can create or reinforce a lack of understanding among people with different beliefs, and make political and social compromise more difficult to come by.
While the situation may not be as dire as Keen suggests in his book, there are clearly some important arguments to consider regarding the effects of the web and social media in particular. The main concerns come down to two things: the possibility that the volume of amateur, user-generated content online is overshadowing better-researched sources, and the questionable ability of users to tell the difference between the two.
Education, the Internet, and Social Media
Although Facebook began at Harvard University and quickly became popular among the Ivy League colleges, the social network has since been lambasted as a distraction for students. Instead of studying, the argument claims, students will sit in the library and browse Facebook, messaging their friends and getting nothing done. Two doctoral candidates, Aryn Karpinski (Ohio State University) and Adam Duberstein (Ohio Dominican University), studied the effects of Facebook use on college students and found that students who use Facebook generally receive a full grade lower—a half point on the GPA scale—than students who do not.Anita Hamilton, “What Facebook Users Share: Lower Grades,” Time , April 14, 2009, www.time.com/time/business/article/0,8599,1891111,00.html. Correlation does not imply causation, though, as Karpinski said that Facebook users may just be “prone to distraction.”
On the other hand, students’ access to technology and the Internet may allow them to pursue their education to a greater degree than they could otherwise. At a school in Arizona, students are issued laptops instead of textbooks, and some of their school buses have Wi-Fi Internet access. As a result, bus rides, including the long trips that are often a requirement of high school sports, are spent studying. Of course, the students had laptops long before their bus rides were connected to the Internet, but the Wi-Fi technology has “transformed what was often a boisterous bus ride into a rolling study hall.”Sam Dillon, “Wi-Fi Turns Rowdy Bus Into Rolling Study Hall,” New York Times , February 11, 2010, http://www.nytimes.com/2010/02/12/education/12bus.html . Even though not all students studied all the time, enabling students to work on bus rides fulfilled the school’s goal of extending the educational hours beyond the usual 8 to 3.
Privacy Issues With Social Networking
Social networking provides unprecedented ways to keep in touch with friends, but that ability can sometimes be a double-edged sword. Users can update friends with every latest achievement—“[your name here] just won three straight games of solitaire!”—but may also unwittingly be updating bosses and others from whom particular bits of information should be hidden.
The shrinking of privacy online has been rapidly exacerbated by social networks, and for a surprising reason: conscious decisions made by participants. Putting personal information online—even if it is set to be viewed by only select friends—has become fairly standard. Dr. Kieron O’Hara studies privacy in social media and calls this era “intimacy 2.0,”Zoe Kleinman, “How Online Life Distorts Privacy Rights for All,” BBC News , January 8, 2010, http://news.bbc.co.uk/2/hi/technology/8446649.stm . a riff on the buzzword “Web 2.0.” One of O’Hara’s arguments is that legal issues of privacy are based on what is called a “reasonable standard.” According to O’Hara, the excessive sharing of personal information on the Internet by some constitutes an offense to the privacy of all , because it lowers the “reasonable standard” that can be legally enforced. In other words, as cultural tendencies toward privacy degrade on the Internet, it affects not only the privacy of those who choose to share their information, but also the privacy of those who do not.
Privacy Settings on Facebook
With over 500 million users, it is no surprise that Facebook is one of the upcoming battlegrounds for privacy on the Internet. When Facebook updated its privacy settings in 2009 for these people, “privacy groups including the American Civil Liberties Union … [called] the developments ‘flawed’ and ‘worrisome,’” reported The Guardian in late 2009.Bobbie Johnson, “Facebook Privacy Change Angers Campaigners,” Guardian (London), December 10, 2009, http://www.guardian.co.uk/technology/2009/dec/10/facebook-privacy .
Mark Zuckerberg, the founder of Facebook, discusses privacy issues on a regular basis in forums ranging from his official Facebook blog to conferences. At the Crunchies Awards in San Francisco in early 2010, Zuckerberg claimed that privacy was no longer a “social norm.”Bobbie Johnson, “Privacy No Longer a Social Norm, Says Facebook Founder,” Guardian (London), January 11, 2010, http://www.guardian.co.uk/technology/2010/jan/11/facebook-privacy . This statement follows from his company’s late-2009 decision to make public information sharing the default setting on Facebook. Whereas users were previously able to restrict public access to basic profile information like their names and friends, the new settings make this information publicly available with no option to make it private. Although Facebook publicly announced the changes, many outraged users first learned of the updates to the default privacy settings when they discovered—too late—that they had inadvertently broadcast private information. Facebook argues that the added complexity of the privacy settings gives users more control over their information. However, opponents counter that adding more complex privacy controls while simultaneously making public sharing the default setting for those controls is a blatant ploy to push casual users into sharing more of their information publicly—information that Facebook will then use to offer more targeted advertising.Kevin Bankston, “Facebook’s New Privacy Changes: The Good, the Bad, and the Ugly,” Deeplinks Blog , Electronic Frontier Foundation, December 9, 2009, http://www.eff.org/deeplinks/2009/12/facebooks-new-privacy-changes-good-bad-and-ugly .
In response to the privacy policy, many users have formed their own grassroots protest groups within Facebook. In response to critiques, Facebook changed its privacy policy again in May 2010 with three primary changes. First, privacy controls are simpler. Instead of various controls on multiple pages, there is now one main control users can use to determine who can see their information. Second, Facebook made less information publicly available. Public information is now limited to basic information, such as a user’s name and profile picture. Finally, it is now easier to block applications and third-party websites from accessing user information.Maggie Lake, “Facebook’s privacy changes,” CNN , June 2, 2010, http://www.cnn.com/video/#/video/tech/2010/05/27/lake.facebook.pr .
Similar to the Facebook controversy, Google’s social networking Gmail add-on called Buzz automatically signed up Gmail users to “follow” the most emailed Gmail users in their address book. Because all of these lists were public by default, users’ most emailed contacts were made available for anyone to see. This was especially alarming for people like journalists who potentially had confidential sources exposed to a public audience. However, even though this mistake—which Google quickly corrected—created a lot of controversy around Buzz, it did not stop users from creating over 9 million posts in the first 2 days of the service.Todd Jackson, “Millions of Buzz users, and improvements based on your feedback,” Official Gmail Blog , February 11, 2010, http://gmailblog.blogspot.com/2010/02/millions-of-buzz-users-and-improvements.html . Google’s integration of Buzz into its Gmail service may have been upsetting to users not accustomed to the pitfalls of social networking, but Google’s misstep has not discouraged millions of others from trying the service, perhaps due to their experience dealing with Facebook’s ongoing issues with privacy infringement.
For example, Facebook’s old privacy settings integrated a collection of applications (written by third-party developers) that included everything from “Which American Idol Contestant Are You?” to an “Honesty Box” that allows friends to send anonymous criticism. “Allowing Honesty Box access will let it pull your profile information, photos, your friends’ info, and other content that it requires to work,” reads the disclaimer on the application installation page. The ACLU drew particular attention to the “app gap” that allowed “any quiz or application run by you to access information about you and your friends.”Nicole Ozer, “Facebook Privacy in Transition - But Where Is It Heading?” ACLU of Northern California, December 9, 2009, www.aclunc.org/issues/technology/blog/facebook_privacy_in_transition_-_but_where_is_it_heading.shtml. In other words, merely using someone else’s Honesty Box gave the program information about your “religion, sexual orientation, political affiliation, pictures, and groups.”Nicole Ozer, “Facebook Privacy in Transition - But Where Is It Heading?” ACLU of Northern California, December 9, 2009, www.aclunc.org/issues/technology/blog/facebook_privacy_in_transition_-_but_where_is_it_heading.shtml. There are many reasons that unrelated applications may want to collect this information, but one of the most prominent is, by now, a very old story: selling products. The more information a marketer has, the better he or she can target a message, and the more likely it is that the recipient will buy something.
Social Media’s Effect on Commerce
Social media on the Internet has been around for a while, and it has always been of some interest to marketers. The ability to target advertising based on demographic information given willingly to the service—age, political preference, gender, and location—allows marketers to target advertising extremely efficiently. However, by the time Facebook’s population passed the 350-million mark, marketers were scrambling to harness social media. The increasingly difficult-to-reach younger demographic has been rejecting radios for Apple’s iPod mobile digital devices and television for YouTube. Increasingly, marketers are turning to social networks as a way to reach these consumers. Culturally, these developments indicate a mistrust among consumers of traditional marketing techniques; marketers must now use new and more personalized ways of reaching consumers if they are going to sell their products.
The attempts of marketers to harness the viral spread of media on the Internet have already been discussed earlier in the chapter. Marketers try to determine the trend of things “going viral,” with the goal of getting millions of YouTube views; becoming a hot topic on Google Trends, a website that measures the most frequently searched topics on the web; or even just being the subject of a post on a well-known blog. For example, Procter & Gamble sent free samples of its Swiffer dust mop to stay-at-home-mom bloggers with a large online audience. And in 2008, the movie College (or College: The Movie ) used its tagline “Best.Weekend.Ever.” as the prompt for a YouTube video contest. Contestants were invited to submit videos of their best college weekend ever, and the winner received a monetary prize.Jon Hickey, “Best Weekend Ever,” 2008, http://www.youtube.com/watch?v=pldG8MdEIOA .
What these two instances of marketing have in common is that they approach people who are already doing something they enjoy doing—blogging or making movies—and give them a relatively small amount of compensation for providing advertising. This differs from methods of traditional advertising because marketers seek to bridge a credibility gap with consumers. Marketers have been doing this for ages— long before breakfast cereal slogans like “Kid Tested, Mother Approved” or “Mikey likes it” ever hit the airwaves. The difference is that now the people pushing the products can be friends or family members, all via social networks.
For instance, in 2007, a program called Beacon was launched as part of Facebook. With Beacon, a Facebook user is confronted with the option to “share” an online purchase from partnering sites. For example, a user might buy a book from Amazon.com and check the corresponding “share” box in the checkout process, and all of his or her friends will receive a message notifying them that this person purchased and recommends this particular product. Explaining the reason for this shift in a New York Times article, Mark Zuckerberg said, “Nothing influences a person more than a trusted friend.”Louise Story, “Facebook Is Marketing Your Brand Preferences (With Your Permission),” New York Times , November 7, 2007, http://www.nytimes.com/2007/11/07/technology/07adco.html . However, many Facebook users did not want their purchasing information shared with other Facebookers, and the service was shut down in 2009 and subsequently became the subject of a class action lawsuit. Facebook’s troubles with Beacon illustrate the thin line between taking advantage of the tremendous marketing potential of social media and violating the privacy of users.
Facebook’s questionable alliance with marketers through Beacon was driven by a need to create reliable revenue streams. One of the most crucial aspects of social media is the profitability factor. In the 1990s, theGlobe.com was one of the promising new startups, but almost as quickly, it went under due to lack of funds. The lesson of theGlobe.com has not gone unheeded by today’s social media services. For example, Twitter has sold access to its content to Google and Microsoft to make users’ tweets searchable for $25 million.
Google’s Buzz is one of the most interesting services in this respect, because Google’s main business is advertising—and it is a highly successful business. Google’s search algorithms allow it to target advertising to a user’s specific tastes. As Google enters the social media world, its advertising capabilities will only be compounded as users reveal more information about themselves via Buzz. Although it does not seem that users choose their social media services based on how the services generate their revenue streams, the issue of privacy in social media is in large part an issue of how much information users are willing to share with advertisers. For example, using Google’s search engine, Buzz, Gmail, and Blogger give that single company an immense amount of information and a historically unsurpassed ability to market to specific groups. At this relatively early stage of the fledgling online social media business—both Twitter and Facebook only very recently turned a profit, so commerce has only recently come into play—it is impossible to say whether the commerce side of things will transform the way people use the services. If the uproar over Facebook’s Beacon is any lesson, however, the relationship between social media and advertising is ripe for controversy.
Social Media as a Tool for Social Change
The use of Facebook and Twitter in the recent political uprisings in the Middle East has brought to the fore the question whether social media can be an effective tool for social change.
On January 14, 2011, after month-long protests against fraud, economic crisis, and lack of political freedom, the Tunisian public ousted President Zine El Abidine Ben Ali. Soon after the Tunisian rebellion, the Egyptian public expelled President Hosni Mubarak, who had ruled the country for 30 years. Nearly immediately, other Middle Eastern countries such as Algeria, Libya, Yemen, and Bahrain also erupted against their oppressive governments in the hopes of obtaining political freedom.Grace Gamba, “Facebook Topples Governments in Middle East,” Brimstone Online , March 18, 2011, www.gshsbrimstone.com/news/2011/03/18/facebook-topples-governments-in-middle-east.
What is common among all these uprisings is the role played by social media. In nearly all of these countries, restrictions were imposed on the media and government resistance was brutally discouraged.Peter Beaumont, “Can Social Networking Overthrow a Government?” Morning Herald (Sydney), February 25, 2011, http://www.smh.com.au/technology/technology-news/can-social-networking-overthrow-a-government-20110225-1b7u6.html . This seems to have inspired the entire Middle East to organize online to rebel against tyrannical rule.Chris Taylor, “Why Not Call It a Facebook Revolution?” CNN , February 24, 2011, http://edition.cnn.com/2011/TECH/social.media/02/24/facebook.revolution . Protesters used social media not only to organize against their governments but also to share their struggles with the rest of the world.Grace Gamba, “Facebook Topples Governments in Middle East,” Brimstone Online , March 18, 2011, www.gshsbrimstone.com/news/2011/03/18/facebook-topples-governments-in-middle-east.
In Tunisia, protesters filled the streets by sharing information on Twitter.Chris Taylor, “Why Not Call It a Facebook Revolution?” CNN , February 24, 2011, http://edition.cnn.com/2011/TECH/social.media/02/24/facebook.revolution . Egypt’s protests were organized on Facebook pages. Details of the demonstrations were circulated by both Facebook and Twitter. email was used to distribute the activists’ guide to challenging the regime.Peter Beaumont, “Can Social Networking Overthrow a Government?” Morning Herald (Sydney), February 25, 2011, http://www.smh.com.au/technology/technology-news/can-social-networking-overthrow-a-government-20110225-1b7u6.html . Libyan dissenters too spread the word about their demonstrations similarly.Chris Taylor, “Why Not Call It a Facebook Revolution?” CNN , February 24, 2011, http://edition.cnn.com/2011/TECH/social.media/02/24/facebook.revolution .
Owing to the role played by Twitter and Facebook in helping protesters organize and communicate with each other, many have termed these rebellions as “Twitter Revolutions”Evgeny Morozov, “How Much Did Social Media Contribute to Revolution in the Middle East?” Bookforum , April/May 2011, www.bookforum.com/inprint/018_01/7222 or “Facebook Revolutions”Eric Davis, “Social Media: A Force for Political Change in Egypt,” April 13, 2011, http://new-middle-east.blogspot.com/2011/04/social-media-force-for-political-change.html . and have credited social media for helping to bring down these regimes.Eleanor Beardsley, “Social Media Gets Credit for Tunisian Overthrow,” NPR , January 16, 2011, http://www.npr.org/2011/01/16/132975274/Social-Media-Gets-Credit-For-Tunisian-Overthrow .
During the unrest, social media outlets such as Facebook and Twitter helped protesters share information by communicating ideas continuously and instantaneously. Users took advantage of these unrestricted vehicles to share the most graphic details and images of the attacks on protesters, and to rally demonstrators.Peter Beaumont, “Can Social Networking Overthrow a Government?” Morning Herald (Sydney), February 25, 2011, http://www.smh.com.au/technology/technology-news/can-social-networking-overthrow-a-government-20110225-1b7u6.html . In other words, use of social media was about the ability to communicate across borders and barriers. It gave common people a voice and an opportunity to express their opinions.
Critics of social media, however, say that those calling the Middle East movements Facebook or Twitter revolutions are not giving credit where it is due.Alex Villarreal, “Social Media A Critical Tool for Middle East Protesters,” Voice of America , March 1, 2011, www.voanews.com/english/news/middle-east/Social-Media-a-Critical-Tool-for-Middle-East-Protesters-117202583.html It is true that social media provided vital assistance during the unrest in the Middle East. But technology alone could not have brought about the revolutions. The resolve of the people to bring about change was most important, and this fact should be recognized, say the critics.Chris Taylor, “Why Not Call It a Facebook Revolution?” CNN , February 24, 2011, http://edition.cnn.com/2011/TECH/social.media/02/24/facebook.revolution .
Key Takeaways
- Social networking sites often encompass many aspects of other social media. For example, Facebook began as a collection of profile pictures with very little information, but soon expanded to include photo albums (like Flickr) and micro-blogging (like Twitter). Other sites, like MySpace, emphasize connections to music and customizable pages, catering to a younger demographic. LinkedIn specifically caters to a professional demographic by allowing only certain kinds of information that is professionally relevant.
- Blogs speed the flow of information around the Internet and provide a critical way for nonprofessionals with adequate time to investigate sources and news stories without the necessary platform of a well-known publication. On the other hand, they can lead to an “echo chamber” effect, where they simply repeat one another and add nothing new. Often, the analysis is wide ranging, but it can also be shallow and lack the depth and knowledge of good critical journalism.
- Facebook has been the leader in privacy-related controversy, with its seemingly constant issues with privacy settings. One of the critical things to keep in mind is that as more people become comfortable with more information out in the open, the “reasonable standard” of privacy is lowered. This affects even people who would rather keep more things private.
- Social networking allows marketers to reach consumers directly and to know more about each specific consumer than ever before. Search algorithms allow marketers to place advertisements in areas that get the most traffic from targeted consumers. Whereas putting an ad on TV reaches all demographics, online advertisements can now be targeted specifically to different groups.
Exercise \(\PageIndex{1}\)
- Draw a Venn diagram of two social networking sites mentioned in this chapter. Sign up for both of them (if you’re not signed up already) and make a list of their features and their interfaces. How do they differ? How are they the same?
- Write a few sentences about how a marketer might use these tools to reach different demographics.


1.2: Green Chemistry Concepts
Agricultural Support
The growing of crops in different farming regions to feed the masses owes its potential greatly to harnessing the power of chemicals such as herbicides, pesticides, fungicides, etc. Although in general we tend to think of the benefits of pesticides, there are a number of issues associated with their use that go well beyond their ability to promote the cultivation and availability of food. For example, DDT (Figure \(\PageIndex{1}\)) is a chemical that has seen much use in the US. Over the period of 1950 to 1980, it was used in agriculture at the rate of more than 40,000 tons each year worldwide and it has been estimated that a total of 1.8 million tons have been produced around the world since the 1940s. In the United States, it was manufactured by numerous companies including Monsanto, Ciba, Montrose Chemical Company, and Pennwalt. More than 600,000 tons (1.35 billion pounds) were applied in the US before it was banned in 1972.
Nature’s Best
The idea that nature produces chemicals that are “green” is a fallacy or a myth. The concept of green deserves some clarification at this point. What is green and what isn’t is actually a matter of nature, quantity, human safety, long term effects, and acute toxicity. Green is generally a term associated with a sustainable (renewable) product or non-toxic process whose employment in society has no acute toxicity and a general favorable life cycle analysis. There are a number of documented chemicals in nature that are extremely toxic even at small doses thus invalidating the idea that nature is “green”. For example, aflatoxin B1, shown below in Figure \(\PageIndex{2}\), is a toxin produced by Apsergillus flavus and A. parasiticus that is one of the most potent carcinogens known. It is a common contaminant of a variety of foods including peanuts, cottonseed meal, corn, and other grains as well as animal feeds. According to the Food and Agriculture Organization, the worldwide maximum levels of aflatoxin B1 is in the range of 1–20 µg/kg in food, and 5–50 µg/kg in dietary cattle feed.
Shown in Figure \(\PageIndex{3}\) below is a derivative of lysergic acid. Lysergic acid, also known as D-lysergic acid and (+)-lysergic acid, is a precursor to a diverse array of ergoline alkaloids produced by the ergot fungus and found in the seeds of Turbina corymbosa (ololiuhqui), Argyreia nervosa (Hawaiian Baby Woodrose), and Ipomoea tricolor (morning glories, tlitliltzin). Amides of lysergic acid, lysergamides (see Fig. 3), are widely used as pharmaceuticals and as psychedelic drugs (LSD). Lysergic acid received its name from the lysis of various ergot alkaloids.
Figure \(\PageIndex{2}\):
Shown above is the diethylamide version of lysergic acid.
https://www.wikiwand.com/en/Lysergic_acid
Again, as already stipulated, nature’s best does not necessarily imply that her products are “green”. Green, by virtue of the product distribution found in nature (e.g. cocaine), can certainly pose serious if not lethal implications for human consumption. We all know that sodium chloride is ubiquitous within nature. It is a common salt that manifests a cubic crystal lattice structure that readily dissolves in water where it is mostly found. Humans consume it in great quantities as a flavorant, seasoning, and preservative. Nevertheless, its mass consumption especially in the US has led to > 65 million people afflicted with high blood pressure while numerous others have all other maladies associated from its overconsumption.
Accidents & Waste Minimization
Waste because of the nature of living processes is a natural consequence. Within the schema of living cell frameworks, the ability to generate waste is considered a clear indication of a “living” system. Waste is a necessary by-product of any work function even if it is heat, light, or some other form of energy by virtue of the intrinsic inefficiencies associated with the utilization of “fuel” or raw materials. For example, even a newborn that is fed on breast milk, a ideal natural food source for babies, does not simply produce a non-material, i.e., heat/energy dissipation, waste product. The problems associated with waste including inherent inefficiencies with using resources are how it builds up and affects the quality of the environment. In general, we cannot prevent waste because everything is subject to entropy.
The crux of the problem associated with waste boils down to safety. As alluded to in the Prezi example above, rust can cause material fatigue or loss of integrity that can compromise functionality. Additionally, chemical processes that produce waste need to adhere to the three general “R”s of Green Chemistry.
- Reduce
- Reuse
- Recycle


45: Population and Community Ecology Last updated Save as PDF Page ID 12637 Boundless Boundless 45.1: Population Demography 45.1A: Population Demography 45.1B: Population Size and Density 45.1C: Species Distribution 45.1D: The Study of Population Dynamics 45.2: Environmental Limits to Population Growth 45.2A: Exponential Population Growth 45.2B: Logistic Population Growth 45.2C: Density-Dependent and Density-Independent Population Regulation 45.3: Life History Patterns 45.3A: Life History Patterns and Energy Budgets 45.3B: Theories of Life History 45.4: Human Population Growth 45.4A: Human Population Growth 45.4B: Overcoming Density-Dependent Regulation 45.4C: Age Structure, Population Growth, and Economic Development 45.5: Community Ecology 45.5A: The Role of Species within Communities 45.5B: Predation, Herbivory, and the Competitive Exclusion Principle 45.5C: Symbiosis 45.5D: Ecological Succession 45.6: Innate Animal Behavior 45.6A: Introduction to Animal Behavior 45.6B: Movement and Migration 45.6C: Animal Communication and Living in Groups 45.6D: Altruism and Populations 45.6E: Mating Systems and Sexual Selection 45.7: Learned Animal Behavior 45.7A: Simple Learned Behaviors 45.7B: Conditioned Behavior 45.7C: Cognitive Learning and Sociobiology


1: Unit I - Basic Principles of Electricity
Learning Objectives
When you have completed the Learning Tasks in this Competency, you will be able to:
- describe the composition of matter and the structure of the atom
- describe the principles of electricity and the theory of current flow
- describe basic types of electrical circuits and their characteristics
- describe electromagnetism
You will use electricity daily. Vehicles and machinery are started and often operated by electricity. Electric tools make the performance of your job easier and more efficient. However, to use electricity safely and effectively, it is important to understand electricity’s terminology and principles.
Thumbnail: Interior Communications Electrician 3rd Class Karla Martinez inspects wiring aboard the aircraft carrier USS Nimitz. (Public Domain; US Navy via Wikipedia )


11: Clarity, Conciseness, and Style Last updated Save as PDF Page ID 20670 Athena Kashyap & Erika Dyquisto City College of San Francisco via ASCCC Open Educational Resources Initiative 11.1: Academic Style This page covers and defines what strong academic writing and style is. 11.2: Punctuation and Style This page covers some of the more obscure style punctuation rules. 11.3: Capitalization This page covers common capitalization rules that students may mistake. 11.4: Commonly Confused Words This page covers words that students commonly misspell or misuse. 11.5: Word Choice This page covers many different aspects of word choice with particular emphasis on slang and strong verbs. 11.6: Sentence Focus This page provides practice on writing and editing clear, focused sentences and covers common mistakes. 11.7: Coordination and Subordination This page covers coordinators, subordinators (subordinating conjunctions), and transitional adverbs -- how to use the and their punctuation. 11.8: Appositives, Adjective Clauses, Verbals This page covers appositives, verbal phrases, and relative/adjective clauses. 11.9: Active vs. Passive Voice This page covers active and passive voice with a number of activities. 11.10: Misplaced and Dangling Modifiers The page covers how to avoid or fix dangling or misplaced modifiers. 11.11: Sentence Variety This page provides instruction and practice on how to vary and develop your sentences using various descriptive phrase and clause strucutres. 11.12: Relative Clauses This page provides specific instruction and practice on using relative clauses, also known as adjective clauses. 11.13: Key Takeaways


2.12: Reading Scholarly Articles
- Explain how to effectively read scholarly articles
Reading Scholarly Articles
For many college assignments, you will be asked to find and read scholarly articles to support arguments in your own writing. Scholarly articles are those written by professionals in their fields of study, intended for other professionals in that field, and published in a venue that professionals in the field use. Professional articles are also often peer-reviewed articles, meaning that other scholars have reviewed the article before publication.
Journal articles generally share these common characteristics:
- Published quarterly or semi-annually in print journals or online
- Follow strict guidelines for organization, writing, and citations
- Include information organized into sections with headings
- Are long and in-depth; 10-20 pages is normal.
- May include graphs or tables but few, if any, images or advertisements.
- Include specialized or field-specific language.
- Present information objectively, without bias.
- Include reference lists and in-text citations.
Scholarly journal articles are different than conventional articles from newspapers, magazines, and websites. They often can be very challenging to read.
Journal articles follow different rules based on the subject or discipline they address. Those written for the humanities use MLA and CMS style and are structured like an essay, while other journal articles follow APA guidelines for organization, writing, and citation.
MLA and CMS
Journal articles written in MLA (Modern Language Association) or CMS (Chicago Manual of Style) are generally organized like an essay, with or without headings, and have the following sections:
- Introduction
- Body
- Conclusion
- Bibliography or Works Cited
- Appendices (if necessary)
These articles use MLA or CMS citation style for layout, citation, and documentation. They make and support arguments, they pay close attention to good prose and writing style, and they include cited references. These types of articles are used in English, History, Modern Languages, and Philosophy studies.
APA Style
APA Style is more commonly used in the sciences and research articles written in the fields of Education, Medicine, Natural Sciences, or Social Sciences. They focus less on prose and writing style, and more on using precise language and specialized terminology. They present studies, propose and test hypotheses, cite relevant research, and describe the results of an experiment. They are generally organized as follows:
- Abstract: Summarize the article
- Key Words
-
Introduction
- Describe the topic
- Identify the problem
- Provide a literature review
- Define the theoretical approach
- State the hypothesis
-
Method
- Describe the model used
- Describe what was done
-
Results
-
Share data (often with tables and
figures) - Describe results
-
Share data (often with tables and
-
Discussion (and/or Conclusion)
- Interpret the results
- Draw conclusions
- Identify limitations
- Share ideas for future areas of study
- References
- Appendices (if necessary)
- Table and/or figures (if necessary, may also be included in the body of the article)
This video reviews each of the components of scholarly journal articles and will walk you through a few examples.
https://lumenlearning.h5p.com/content/1290915998870528678/embed
You can view the transcript for “Annotating a Journal Article” here (opens in new window) .
Contributors and Attributions
- Modification, adaptation, and original content. Provided by : Lumen Learning. License : CC BY: Attribution
- Annotating a Journal Article. Provided by : Excelsior Online Reading Lab. Located at : https://owl.excelsior.edu/orc/what-to-do-while-reading/annotating/annotating-a-journal-article/ . License : CC BY: Attribution
- Image of protractors. Authored by : Dean Hochman. Located at : https://flic.kr/p/o4HPL7 . License : CC BY: Attribution
- Scholarly sources defined. Provided by : Clackamas Community College Librar. Located at : http://libguides.clackamas.edu/c.php?g=775297&p=5561191 . License : CC BY: Attribution


10.2: Love and Attraction Theory
One of the most important factors in interpersonal attraction is similarity: the more similar two people are in attitudes, background, and other traits, the more probable it is that they will like each other. Contrary to popular belief, opposites do not usually attract. Although physical attraction may take precedence in the early stages of a romantic relationship, similarity and other compatibility factors become more important later on.
Sternberg’s Triangular Theory of Love
Psychologist Robert Sternberg describes love based on combinations of three components: passion, intimacy, and commitment. When two people share all three, they are said to be in a state of consummate love. This combination is considered to be an ideal type of love, but is also relatively difficult to maintain for a long period of time.
A relationship based on a single component is less likely to survive than one based on two or three components.
Contributors and Attributions
CC Licensed Content, Shared Previously
- Attraction and Love Theory. Authored by: Boundless. Located at: www.boundless.com/psychology/textbooks/boundless-psychology-textbook/social-psychology-20/social-behavior-105/attraction-loving-397-12932/. License: CC BY-SA: Attribution-ShareAlike


11.3: Reading- Phases of the Hydrologic Cycle
Because of the unique properties of water, water molecules can cycle through almost anywhere on Earth. The water molecule found in your glass of water today could have erupted from a volcano early in Earth history. In the intervening billions of years, the molecule probably spent time in a glacier or far below the ground. The molecule surely was high up in the atmosphere and maybe deep in the belly of a dinosaur. Where will that water molecule go next?
Three States of Water
Water is the only substance on Earth that is present in all three states of matter—as a solid, liquid or gas. (And Earth is the only planet where water is present in all three states.) Because of the ranges in temperature in specific locations around the planet, all three phases may be present in a single location or in a region. The three phases are solid (ice or snow), liquid (water), and gas ( water vapor ). See ice, water, and clouds (figure 2).
The Water Cycle
Because Earth’s water is present in all three states, it can get into a variety of environments around the planet. The movement of water around Earth’s surface is the hydrologic (water) cycle (figure 3).
Most of Earth’s water is stored in the oceans where it can remain for hundreds or thousands of years. The oceans are discussed in detail in the chapter Earth’s Oceans.
Water changes from a liquid to a gas by evaporation to become water vapor. The Sun’s energy can evaporate water from the ocean surface or from lakes, streams, or puddles on land. Only the water molecules evaporate; the salts remain in the ocean or a fresh water reservoir.
The water vapor remains in the atmosphere until it undergoes condensation to become tiny droplets of liquid. The droplets gather in clouds, which are blown about the globe by wind. As the water droplets in the clouds collide and grow, they fall from the sky as precipitation. Precipitation can be rain, sleet, hail, or snow. Sometimes precipitation falls back into the ocean and sometimes it falls onto the land surface.
For a little fun, watch this video. This water cycle song focuses on the role of the sun in moving H 2 O from one reservoir to another. The movement of all sorts of matter between reservoirs depends on Earth’s internal or external sources of energy:
This animation shows the annual cycle of monthly mean precipitation around the world.
When water falls from the sky as rain it may enter streams and rivers that flow downward to oceans and lakes. Water that falls as snow may sit on a mountain for several months. Snow may become part of the ice in a glacier, where it may remain for hundreds or thousands of years. Snow and ice may go directly back into the air by sublimation , the process in which a solid changes directly into a gas without first becoming a liquid. Although you probably have not seen water vapor sublimating from a glacier, you may have seen dry ice sublimate in air.
Snow and ice slowly melt over time to become liquid water, which provides a steady flow of fresh water to streams, rivers, and lakes below. A water droplet falling as rain could also become part of a stream or a lake. At the surface, the water may eventually evaporate and reenter the atmosphere.
A significant amount of water infiltrates into the ground. Soil moisture is an important reservoir for water (figure 4). Water trapped in soil is important for plants to grow.
Water may seep through dirt and rock below the soil through pores infiltrating the ground to go into Earth’s groundwater system. Groundwater enters aquifers that may store fresh water for centuries. Alternatively, the water may come to the surface through springs or find its way back to the oceans.
Plants and animals depend on water to live and they also play a role in the water cycle. Plants take up water from the soil and release large amounts of water vapor into the air through their leaves (figure 5), a process known as transpiration .
An online guide to the hydrologic cycle from the University of Illinois is found here.
People also depend on water as a natural resource. Not content to get water directly from streams or ponds, humans create canals, aqueducts, dams, and wells to collect water and direct it to where they want it (figure 6).
| Table 1. Water Use in the United States and Globally | ||
|---|---|---|
| Use | United States | Global |
| Agriculture | 34% | 70% |
| Domestic (drinking, bathing) | 12% | 10% |
| Industry | 5% | 20% |
| Power plant cooling | 49% | small |
It is important to note that water molecules cycle around. If climate cools and glaciers and ice caps grow, there is less water for the oceans and sea level will fall. The reverse can also happen.
How the water cycle works and how rising global temperatures will affect the water cycle, especially in California, are the topics of this Quest video. Learn more here.
Contributors and Attributions
- The Water Cycle. Provided by : CK-12. Located at : http://www.ck12.org/student/ . License : CC BY-NC: Attribution-NonCommercial


2.8: Strict Four-Voice Composition - A Brief History of basso continuo Keyboard-Style Voice-Leading
Basso continuo emerged in the seventeenth century as a shorthand notation for keyboardists (typically church organists) who were accompanying a soloist or small ensemble performing a work originally composed for a larger group. For example, if two or three singers were tasked with performing an eight-voice choral work, they could select the most prominent parts to sing, while an organist could cover the rest. Performing five or six lines of contrapuntal choral music could be a significant challenge, so organists needed a way to condense the texture while still preserving the core musical structure to support the vocalists.
The thorough bass emerged as that shortcut. The “thorough” or “continuous” bass is a musical line that includes the lowest note at any given time. Usually, works would not include a single part that could function as this line, so the organist would alternate between voices, as they exchanged registers or took rests. The resulting line, unline the regular “bass” part, was “continuous” (or “thorough”)—hence the name thoroughbass or basso continuo .
A good musician could perform this bass line, and with an eye (or ear) on the vocal parts and with knowledge of how to improvise good voice-leading, that musician could accompany the thoroughbass line with chords that made musical sense. (This is the original meaning of the term accompany—to accompany a bass line with chords. The fact that keyboardists did this in the context of supporting a soloist or small ensemble led to that term later being applied to any situation where a keyboardist accompanied spotlight performers.)
As this technique grew, publishers began publishing thoroughbass reductions of large-ensemble pieces to support smaller groups of musicians. In these publications, figures (numbers above or below the bass line) were included—sometimes only for difficult or non-standard chords, and eventually for most chords, enabling more amateur musicians, as well as students, to make use of the technique. These bass lines with figures became known as “figured bass” lines.
J.S. Bach, Flute Sonata in C Major, ii., BWV 1033. The upper part is played by the flute, the lower part is the basso continuo line, played by a keyboardist who uses the numbers below the staff (figures) to guide the chords played above this bass line.
To this day, harpsichordists performing in Baroque ensembles will often put their left hand to the same “bass” line that the cellos play, and will improvise right-hand chords (with contrapuntally sound embellishment) according to the figures provided with the bass line.
Though most music students are not Baroque keyboard specialists in training, thoroughbass, or basso continuo , can be a valuable tool in the study of harmony and voice-leading. In the study of harmony, a thoroughbass line can play a valuable role as a harmonic reduction of a complex texture, in order to example and understand better the harmonic skeleton underlying a passage. In aural dictation, transcription, and analysis, the bass line and the melody are often the most prominent (and most important) lines in a passage, and knowing how the inner voices tend to relate to the bass line and melody can aid in a number of listening and aural-analysis tasks. In voice-leading, the basso continuo texture affords a straightforward environment in which to make a gradual, staged progression through the intricacies of writing musical lines in a harmonic texture—and to do so without paying significant attention to harmony.


23.7: Intramolecular Aldol Reactions
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Objectives
After completing this section, you should be able to
- write an equation to illustrate an intramolecular aldol reaction.
- identify the product formed when a given dicarbonyl compound undergoes an intramolecular aldol condensation.
- identify the dicarbonyl compound which, when treated with a suitable base, could be used to prepare a given cyclic enone by an intramolecular aldol condensation.
Study Notes
“Intramolecular ” means “within the same molecule.” You have already seen some examples of intramolecular reactions in previous chapters. Another term for intramolecular aldol reaction is “internal aldol reaction.”
Intramolecular aldol reaction
Molecules which contain two carbonyl functionalities have the possibility of forming a ring through an intramolecular aldol reaction. The term “Intramolecular” means “within the same molecule.” In this case, it means that the enolate donor and the electrophilic acceptor of an aldol reaction are contained in the same molecule such as dialdehydes, keto aldehydes, or diketones. In these cases, the small distance between the donor and acceptor leads to faster reaction rates for intramolecular condensations making intermolecular condensations (which require two molecules to collide in solution) less favorable.
In most cases multiple sets of α-hydrogens need to be considered when determining the donor/acceptor roles for the reaction, which might lead to a mixture of products. The intramolecular aldol reaction of a 1,5-diketone, 2,6-heptanedione, could possibly yield either the six-membered ring product, 3-methyl-2-cyclohexenone, or the four-membered ring product, (2-methylcyclobutenyl)ethanone. However, the cyclohexanone product is exclusively formed.
This product selectivity is possible due to all of the steps of the mechanism being reversibly, which tends to produce the most stable product. As with most ring forming reactions, five and six membered rings are preferred due to their relative lack of ring strain compared to other sized rings (See Sections 4.4 & 4.5). Once equilibrium is reached, the relatively strain free and therefore more thermodynamically stable, cyclohexanone product will be preferably formed.
Example
Similar analysis can be used to predict the products of other intramolecular aldol reactions. In a similar reaction, 1,4-diketones, such as 2,5-hexanedione, only form the five-membered ring product, ex. 3-methyl-2-cyclopentenone, without any of the possible cyclopropane product forming.
Example
Worked Example
Please draw the expected product of an intramolecular aldol condensation with the following molecule:
- Answer
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Analysis : 6-Oxoheptanal has three unique sets of alpha-hydrogens which could be deprotonated to form an enolate. Selecting the correct set involves analyzing the carbonyl reactivity’s along with the possible ring sizes of the products.
Solution: Once the preferred alpha-hydrogens are determined go through the steps discussed in the previous sections to determine the aldol condensation product. Remember to form the aldol intermediate first.
Exercises \(\PageIndex{1}\)
1) Briefly explain why the molecule, 2,4-pentanedione, when reacted with a base would mostly likely not produce an intramolecular aldol condensation product.
2) Draw the product of the following aldol condensation:
- Answers
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1) 2,4-Pentanedione like other 1,3-Diketones have particularly acidic alpha-hydrogens between the two carbonyl. When base is applied these will be the first to deprotonate and form an enolate. For an intramolecular aldol condensation to occur an alpha-hydrogen one of the methyl groups would have to be removed which would be difficult.
2)


1.5: Week 5 - Ethos (Character, Credibility)
Ethos (sometimes called an appeal to ethics), then, is used as a means of convincing an audience via the authority or credibility of the persuader, be it a notable or experienced figure in the field or even a popular celebrity. We determine Ethos by looking at the tone, style and credibility of the speaker, the sources and the publication. We determine it by establishing the authority and credibility of the argument and the arguer. It is an essential element of Aristotle’s model of rhetorical appeals. The word Ethos means “character” or “credibility” or “qualifications.”
- When someone asks, “What right do you have to speak on this issue?” or “What are your qualifications to speak on this matter?” They are asking for character and credibility, or Ethos .
- When you offer credentials, experience, appeals to shared beliefs and values or other appeals to emotion as “support” in an argument, you are using Ethos .
- Proper use of Ethos in an argument will offer appeals to emotions, values and beliefs that: are shared with the readers/audience, do NOT hide or obscure the fact that the argument has little to no logical support, and do not unfairly promote hatred or fear without sufficient cause.
- View the handout: Ethos (Opens in new window)
- View the following video: What is Character (Ethos)? (Opens in new window) , https://www.youtube.com/watch?v=ano2hBbiaiI
- View the following video: Five Ways to Persuade with Character (Ethos) (Opens in new window) , https://www.youtube.com/watch?v=D4c75dYQoFo


7.5.6: Monkeypox (Mpox)
Mpox or monkeypox is caused by a virus related to smallpox, and was named so because it was first discovered in small primates. Mpox can be transmitted via direct contact with an infected person (including sexual contact), as well as indirect contact by fomite (surfaces or objects touched by the infected person). There are two types of Mpox (called “clades”), one has a much lower case-fatality rate than the other (10% vs. <1%). In 2022 there was an outbreak of the latter strain of Mpox that traveled around the world and caused over 94,000 cases, many of which had not previously reported Mpox. Fortunately, a vaccine is available that has a 70% vaccine effectiveness measure, which means that vaccinated cases are 70% lower than unvaccinated cases (Mpox, 2024).


21.2.4: The Midpoint
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Learning Outcomes
- Find the midpoint between two numbers.
- Sketch the midpoint of two numbers on a number line.
As the word sounds, "midpoint" means "the point in the middle". Finding a midpoint is not too difficult and has applications in many areas of statistics, from confidence intervals to sketching distributions, to means.
Finding the Midpoint Between Two Numbers
If we are given two numbers, then the midpoint is just the average of the two numbers. To calculate the midpoint, we add them up and then divide the result by 2. The formula is as follows:
Definition: the Midpoint
Let \(a\) and \(b\) be two numbers. Then the midpoint, \(M\) of these two numbers is
\[M\:=\frac{a+b}{2} \label{midpoint}\]
Example \(\PageIndex{1}\)
Find the midpoint of the numbers \(3.5\) and \(7.2\).
Solution
The most important thing about finding the midpoint is that the addition of the two numbers must occur before the division by 2. We can either do this one step at a time in our calculator or we can enclose the sum in parentheses. In this example we will perform the addition first:
\[3.5+7.2\:=\:10.7 \nonumber\]
Now we are ready to divide by 2:
\[\frac{10.7}{2}=5.35 \nonumber\]
Thus the midpoint of 3.5 and 7.2 is 5.35.
Example \(\PageIndex{2}\)
A major topic in statistics is the confidence interval which tells us the most likely interval that the mean or the proportion will lie in. Often the lower and upper bound of the confidence interval are given, but the midpoint of these two numbers is the best guess for what we are looking for. Suppose a 95% confidence interval for the difference between two means is -1.34 and 2.79. Find the midpoint of these numbers, which is the best guess for the difference between the two means.
Solution
We use the formula for the midpoint (Equation \ref{midpoint}):
\[M\:=\:\frac{a+b}{2}=\:\frac{-1.34+2.79}{2} \nonumber\]
Now let's use a calculator. We will need parentheses around the numerator:
\[\left(-1.34+2.79\right)\div2\:=\:0.725 \nonumber\]
Thus, the midpoint of the numbers -1.34 and 2.79 is 0.725.
Sketching the Midpoint on a Number Line
Visualizing the midpoint can often reveal it much better than just writing down its value. The diagrams are of fundamental importance in statistics.
Example \(\PageIndex{3}\)
Sketch the points -3, 5 and the midpoint of these two numbers on a number line.
Solution
We start by finding the midpoint using the midpoint formula (Equation \ref{midpoint}):
\[M\:=\frac{\:-3+5}{2}=\left(-3+5\right)\div2\:=\:1 \nonumber\]
Now we sketch these three points on the number line:
Example \(\PageIndex{4}\): hypothesis testing
Another application of the midpoint involves hypothesis testing. Sometimes we are given the hypothesized mean, which is the midpoint. We are also given the sample mean, which is either the left or right endpoint. The goal is to find the other endpoint. Suppose that the midpoint (hypothesized mean) is at 3.8 and the right endpoint (sample mean) is at 5.1. Find the value of the left endpoint.
Solution
It helps to sketch the diagram on the number line as shown below.
Now since 3.8 is the midpoint, the distance from the left endpoint to the midpoint is equal to the distance from 3.8 to 5.1. The distance from 3.8 to 5.1 is:
\[5.1\:-\:3.8\:=\:1.3 \nonumber\]
Therefore the left endpoint is 1.3 to the left of 3.8. This can be found by subtracting the two numbers:
\[3.8\:-\:1.3\:=\:2.5 \nonumber\]
Therefore the left endpoint is at 2.5.
Exercise
Suppose that the midpoint (hypothesized proportion) is at 0.31 and the left endpoint (sample proportion) is at 0.28. Find the value of the right endpoint.


3.17: Scatterplots (4 of 5)
Learning Objectives
- Use a scatterplot to display the relationship between two quantitative variables. Describe the overall pattern (form, direction, and strength) and striking deviations from the pattern.
We now look at two more examples:
Example
Average Length of Pregnancy
What is the relationship between an animal’s lifespan and the length of its pregnancy? To investigate this question, we have data from 40 different species of animals living in captivity. We use average lifespan as the explanatory variable, x . The average length of pregnancy is the response variable, y . (Source: Allen J. Rossman and Beth L. Chance, Workshop Statistics: Discovery with Data and Minitab [Key College Publishing, 2001]. Original source: World Almanac and Book of Facts, 1993 [World Almanac, 1993].)
What can we learn about the relationship from the scatterplot?
The direction of the relationship is positive. An increase in lifespan is associated with an increase in pregnancy length. In other words, animals that live longer tend to have longer pregnancies. The form of the relationship is linear. The relationship is moderately strong .
Is there an outlier? There is a data point that deviates from the rest of the data because it has large x – and y -values. This is the elephant. Elephants live a long time (large x -value) and have a long pregnancy (large y -value). So the elephant is an outlier in the distribution of both the lifespan and the pregnancy variables. But this data point follows the positive direction of the data and fits the linear pattern. With respect to the form and direction of the relationship between the variables, this point is not an outlier.
Notice that the variation in pregnancy length is larger for animals that live longer. For example, animals that live 5 years have pregnancies that range from about 30 days to 120 days. The short, red vertical line on the left illustrates this range. Animals that live 12 years have pregnancies that vary more, ranging from about 60 days to over 400 days. The longer red vertical line on the right illustrates this range. So the relationship is stronger for animals with shorter lifespans.
Example
Fuel Usage
When you drive a car, what is the relationship between the speed you drive and the amount of gas the car uses? In this study, engineers measured the amount of fuel (in liters) used to drive 100 kilometers. They made these fuel measurements for a car driving at a fixed speed (in kilometers per hour). They then made fuel measurements for different fixed speeds.
What can we learn about the relationship from the scatterplot?
The data describe a relationship that decreases, then increases, so the direction of the relationship is negative and then becomes positive. In other words, at slow speeds, the car uses a lot of fuel. The amount of fuel decreases rapidly to a low point when the speed is 60 kilometers per hour, so the car uses the least amount of fuel at a speed of 60 km/h. The amount of fuel increases gradually for speeds above 60 km/h. This forms a curvilinear relationship that is very strong . All of the data fit a smooth curve.
Is there an outlier? The point (10, 21) lies above the rest of the data. With respect to speed ( x ), this point is not an outlier. The x -value does not deviate from the pattern for the other x -values in the data. In this study, it appears that the engineers varied the speeds by increments of 10 km/h. However, the y -value is much higher than the other y -values. With respect to fuel usage, this point is an outlier. But the point fits the overall curvilinear pattern in the data, so with respect to direction and form, this point is not an outlier.
Comment
In Summarizing Data Graphically and Numerically , we developed a method for identifying outliers in a distribution of one quantitative variable. The method was the 1.5 * IQR rule. In a scatterplot, you can use this rule to determine if the x -value of a point is an outlier with respect to the x -values in data. Similarly, you can use this rule to determine if a y -value of a point is an outlier with respect to the y -values in the data. However, this rule does not help us identify a point that deviates from the overall pattern in the data.
Is there a method to identify outliers that deviate from the overall pattern in a scatterplot? The answer is yes, but we do not discuss these techniques in this course. For now, just look at the scatterplot and see if a point deviates from the overall pattern. In other words, see if the point deviates from the direction and form of the data. We will see later that this type of outlier can influence measures of center and spread for two quantitative variables.
Contributors and Attributions
- Concepts in Statistics. Provided by : Open Learning Initiative. Located at : http://oli.cmu.edu . License : CC BY: Attribution


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1.4.2: Reading and Review Questions
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In Chapter XV, how does Cabeza de Vaca reconcile his practicing the Indians’ healing with his own cultural beliefs?
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In Chapter XV, what information about the Indians’ culture does Cabeza de Vaca convey? How?
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In Chapter XVI, how do the Indians treat the Spaniards? Why?
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In Chapter XIX, what does Cabeza de Vaca learn of the people who came in the boat of Peñalosa and Tellez? What is his attitude toward what he learns? How do you know?
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In Chapter XXI, separated from the Indians and his companions, naked and lost, how does Cabeza de Vaca survive the winter cold? What is his attitude toward his survival? How do you know?