AP Chemistry Post-exam Supplemental Reading

I have provided you with several pieces for you to read. I would like to have a class discussion of the content of these pieces as well as whatever else comes to mind as we talk. To prepare for that discussion I would like you to take a little time to answer a few questions. Type up your answers and submit them through the Google Classroom assignment prior to the day of our discussion. Answers should be no more than about 500 words.

Article 1, “The Chemist”

Roald Hoffmann sees creation and discovery as different things. Typically, art is understood to involve an act of creation while science simply discovers what already exists. In this essay Prof. Hoffmann describes the creativity involved in the synthesis of new molecules. Also, he makes the case that the act of discovering how plants make an important precursor to chlorophyll is in fact the result of the creative powers of the chemists involved.

1. What is discovery? What is creation? What makes them different? In your answer refer to one example not mentioned in the essay.
2. What is the central problem which prompts the question in the mind of Roald Hoffmann (the author) about the question of creation vs. discovery? Give a brief summary of the specific scientific context he talks about.
3. Do scientists merely discover while artists create? Is it possible that artists, by making something new and unique, also participate in discovering truths that exist but were otherwise hidden? Support your answer with two or more examples.

Article 2, “Theory and Practice”

In this article we see a small part of the interaction between a theoretical chemist (Roald Hoffmann) and an experimental chemist (Margarita Rybinskaya). Hoffmann is intrigued by an idea for an extension of Rybinskaya’s work. He proposes a collaboration but problems of communication make for an interesting outcome.

1. Describe the experimental result that inspired Hoffmann. What was his proposed extension?
2. What role does theory play in the interaction between the two scientists?
3. What role does experiment play in the interaction depicted in the essay?
4. What is theory and what is experiment?

Article 3, “Carbon”

Primo Levi was a chemist and a survivor of Auschwitz. His writings combined a sensitive observer of the human condition with deep scientific understanding and knowledge of the limits of that understanding. In this essay he imagines the history of a single atom of carbon and thereby reveals the deep connections between all living things and their environment.

1. What is the significance of the fact that plants can cause an atom of carbon to “be nailed there by a ray of the sun.“?
2. In what sense is carbon dioxide an “impurity” in the Earth’s atmosphere? What implications does that have for the importance of photosynthesis?
3. What does Levi (the author) mean when he writes, “In this downward course, which lead to equilibrium and thus death, life draws a bend and nests in it.”? Consider what you have learned about thermodynamics and the importance of entropy in spontaneous processes. Should life even be possible? Why or why not?

Article 4, “Secrets in the Ice”

This piece is part of the 11^th chapter of the book Locust: The Devastating Rise and Mysterious Disappearance of the Insect that Shaped the American Frontier by Jeffrey A. Lockwood (Basic Books, 2004). It follows a detailed look at the history, sociology, economics, biology, and ecology of the swarms of locusts that formerly blotted out the sun and covered the landscape for hundreds of square miles, eating everything above ground. The writer is a grasshopper biologist at the University of Wyoming. He has a particular passion for the creatures responsible for the plagues of locusts that regularly swept over the west and mid-west in the late 1800s and early 1900s. The effects of the plagues were devastating and much was undertaken to stop the swarms but nothing helped. Then suddenly there were no more plagues. Though this was a big deal it was overshadowed by the events of World War I and since not appearing is a literal non-event, there was not much reporting about it. It was this mystery that most interested Prof. Lockwood.

There are a few things for which the whole book provides context but which are missing in the text of this chapter. For one thing, there are two similar species of grasshopper which were often confused for one another: Melanoplus sanguinipes and Melanoplus spretus. It is spretus which is the Rocky Mountain Locust, a fact established in part based on work by Prof. Lockwood. Species of grasshoppers can be difficult to distinguish with the only feature separating species often being the shape of the male genitalia. Despite descending onto human-inhabited areas in swarms of literally trillions of insects very few individuals were added to museum collections. Once the creatures disappeared it became nearly impossible to study them. Prof. Lockwood wanted to follow up on reports of glaciers in the Rocky Mtns. in which large numbers of frozen grasshoppers could be found. The glaciers are remote and accessing them would require mounting an expensive expedition.

Here are a few questions for you to consider after reading this chapter.

1. Think back to before you read this article. How would you have answered the following question? How do scientists choose what to study and why do they do what they do?
2. Prof. Lockwood says that there is an ideal of objectivity in science. What is objectivity and to what does it apply?
3. There was a good chance that the glaciers containing frozen grasshoppers had already melted, leaving the grasshopper bodies to rot in the summer sun. It had been about thirty years since the last scientific expedition and glaciers are melting quickly. Funding a new expedition was therefore a risk since nothing may have come of it. And yet, the Office of Research at the Univ. of Wyoming ultimately did award Prof. Lockwood some funds to mount an expedition. Why?
4. What are some of the ways that scientists do in fact choose what they will study? In particular, what does the phrase “the lead sheep in the flock” mean in this context?
5. What does Prof. Lockwood think is a good way to choose what questions to ask and how to pursue them? Do you agree?
6. How did reading this piece change your thinking about how and why people do science?