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^{14}C decays via B

^{-}emission, and 18.0% of our body's mass is carbon.

a) Write out the decay scheme of carbon-14 and show the end product. (A neutrino is also produced.)

answer:

^{14}

_{6}C ------> e

^{-}+

^{14}

_{7}N + v

_{e}

b) Neglecting the effects of the neutrino, how much kinetic energy (in MeV ) is released per decay? The atomic mass of C-14 is 14.003242 u.

No idea where to begin tried using E = mc

^{2}did not get the right answer.

c) How many grams of carbon are there in a 76.0 kg person?

no idea how to do this.

d) How many decays per second does this carbon produce? (Hint: Assume activity of C-14 is about 0.255 Bq per gram of carbon.)

No idea about this one either.

Any help would be greatly appreciated.