HW Solutions #10
- Page ID
- 2844
1. How is nuclear fission different from nuclear fusion? Why are both of these nuclear processes exothermic?
2. Plutonium-238 is potential source for heart pacemaker batteries with a 87.74 year half-life. Calculate the activity in units of curies for 0.50 g of pure plutonium-238 used is a pacemaker battery. Why is Plutonium-238 a good power source in a pacemaker?
3. What is the age of mummified primate skin that contains 4.125% of the original quantity of 14C?
4. Radioactive Rn-222 is known to accumulate in basement of buildings and constitute a health risk.
- What is the parent primary natural radionuclide the produces the Rn-222?
- Write the reaction for the nuclear decay of radon-222.
- Why are none of the intermediate radionuclides and the parent radionuclide considered a health risk?
5. Cobalt-60 has a half-life of 5.26 yr. The cobalt-60 in a radiotherapy unit must be replaced when its radioactivity falls 75% of the original sample. If the original sample was purchased in July 2008, when should you replace the cobalt-60 sample?
6. What is the difference between electrons and β- particles?
7. Write the nuclear reactions for the following:
- the α decay of 238Pu
- the negatron (negative beta particle) decay of 60Co
- the positron decay of 11C
- the electron capture decay of 208Bi
- the neutron-induced fisson of 235U into 144Ba, γ and two neutrons
8. Write the balanced equation for the beta decay of 14C.
- 146C → 147N + 0-1e- + ν
9. Write the balanced equation for the positron emission decay of 22Na.
- 2211Na → 2210Ne + 0+1e+ + ν
10. Write the balanced equation for electron capture in 207Bi.
- 20783Bi + 0-1e- → 20782Pb + ν
11. Write the balanced equation for the alpha decay of 238U.
- 23892U → 23490Th + 42He