Chem 147 Midterm Examination 3 February 2011

First letter of your last name:

Name:

Last Name, First Name

Please CHECK that there are total of 4 pages (a total of 7 problems, which, with one, noted exception, are worth 15 pts each for a total of 100 points) on the exam.

INSTRUCTIONS: All of the questions in this exam can be answered in one or two sentences or, in some cases, a short list. I thus expect you to answer in the space provided. (With so many students and no TA, I’m forced to value brevity; you have been warned!). Good luck!

1. Why doesn’t the start of nuclear fusion blow a star apart due to the heat that it produces?

2. Why does the cosmic microwave background reflect conditions in the Universe some 380,000 years after the Big Bang?

3. Check out the periodic table on the front page. Given the locations of arsenic and phosphate, do you think that alien life elsewhere might use arsenate diesters in place of phosphodiesters in its biopolymers? Argue for or against.

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4. Why might the primordial atmosphere of the Earth been relatively reduced? Why has the Earth's atmosphere become more oxidized over the last 4 billion years?

5. What is the bulk composition of Mercury, and how do we know this?

6. Which is the largest planet, and why is it so large? (10 pts)

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7. Does Miller-Urey chemistry produce nucleobases? If so, how? And, if not, how might they have been produced abiologically?

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