NUCLEAR CHEMISTRY

1. how an atom is referred to in nuclear chemistry
5. a very heavy nucleus splits into more stable nuclei of intermediate mass
6. light mass nuclei combine to form a heavier mare stable nucleus
8. use heat for nuclear reactors to produce electrical energy
9. neutron absorbing rods that help control the reaction by limiting the number of free neutrons
13. a reaction that affects the nucleus of an atom
14. the protons and neutrons of an atom collectively
17. unit used to measure nuclear radiation
19. a reaction in which the material that starts the reaction is also on on the products and can start another reaction
20. an electron emitted from the nucleus during radioactive decay

2. the minimum amount of nuclide that provides the number of neutrons needed to sustain a chain reaction
3. the time required for half the atoms of radioactive nuclide to decay
4. 2 protons and 2 neutrons emitted from the nucleus during decay
7. the difference between the mass of an atom and the sum of the masses of its protons, neutrons and electrons
10. use controlled fission chain reactions to produce energy or radioactive nuclides
11. a change in the identity of a nucleus as a result of a change in the number of its proton
12. stable nuclei cluster over a range of neutron-proton ratios
15. the spontaneous disintegration of a nucleus into a slightly lighter nucleus accompanied by emission of radiation
16. used to slow down the fast neutrons produced in fission
18. radiation absorbing material that is used to decrease exposure to radiation in nuclear reactors