AP Chemistry - Nuclear Worksheet #6
Fission
1. Why is it easier for a nucleus to capture a neutron than a proton? 
 
2. What does the term thermal neutron mean? 
 
3. What is meant by a fissile isotope? 
 
4. What fact about the fission of uranium-235 makes it possible for a chain-reaction to occur? 
 
5. Complete the following nuclear equation by supplying the symbol for the other product of the fission. Both products of the fission below are unstable. What is the most likely way for each of them to decay - by alpha emission, beta emission, or by positron emission? Explain. 


 

6. Why would there be a subcritical mass of a fissile isotope? (Why isn't any mass of uranium-235 critical?) 
 
7. What purpose is served by a moderator in a nuclear reactor? 
 
8. What does the term multiplication factor mean in connection with a nuclear reactor? 
 
9. If in a pressurized-water reactor a break occurs in a primary coolant line, what is one of the first things to happen with the reactor?
 
10. How might hydrogen gas be generated following a loss-of-coolant accident in a reactor? 
 
11. What advantages does molten sodium offer as a primary coolant in a nuclear power plant? 
 
12. What does it mean when uranium-238 is described as a fertile isotope? 
 
13. Write the nuclear equation for the breeding of plutonium-239 from uranium-238.