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11. When three helium-4 atoms fuse to form an atom of carbon-12,
is there a gain, or loss, of mass, and how much? Is energy absorbed,
or given off, and how much? (Recall that carbon-12 is the standard
for the amu scale, with a mass of exactly 12 amu.) 12. When two oxygen-16 atoms fuse in a reaction at the centers of very heavy stars to produce an atom of sulfur-32, how much mass is lost, and how much energy released? (Mass of 32S = 31.9721 amu; 16O = 15.9949.) 13. When an atom of nickel-60 and a helium-4 atom fuse to form zinc-64, what is the change in mass? Is energy given off, or absorbed, and how much? 14. Thorium-232 is the beginning of a radioactive decay series (similar to the two uranium series) in which six alpha particles and four beta particles are emitted before a stable isotope is reached. What is the final stable element, and what is its mass number? 15. Plutonium-241 is the beginning of a decay series during which eight alpha and five beta particles are emitted. What is the final stable element, and what is its mass number? |
