AST 248: The Search for Life in the Universe

1. How many protons does a C¹² nucleus have, and how many neutrons?
2. C¹⁴ is radioactive. It decays when one of its neutrons changes to a proton, an electron and an antineutrino.
   1. What nucleus is thereby created?
   2. The halflife of C¹⁴ is 5730 years. If you had a sample containing 2 million atoms of C¹⁴, how long would it be until only 500,000 atoms of C¹⁴ remained?
3. What is the single property of a star at birth that determines which kind of death it will have (if it is not in a close double star system)?
4. How do most heavy elements get introduced into the interstellar medium from which planets and people can be eventually made?
5. What broad class of molecules are the most complex that are found in the interstellar medium?
6. What is the frequency of spin-flip radiation from Hydrogen atoms? Why is this radiation important?
7. What are the three main pieces of evidence that the universe began from, or at least passed through, a period of extremely high densities and/or temperatures, commonly called the Big Bang?
8. What is the approximate age of the universe, and how can this be estimated from Hubble's Constant?