Nuclear Chemistry

3. Fusion occurs in the ____.
4. Unstable nuclei are ____.
5. Minimum mass required for chain fission reaction is ____ mass.
7. Man-made elements are by ___ of an isotope with nuclear "bullets".
8. The nucleus makes up almost all the ____ of the atom.
10. Large nuclei need a neutron to _____ ratio of over 1:1 to be stable.
12. The time it takes half the mass of a radioactive isotope to decay is called ______ life.
13. Changing into another element through radioactive decay.
14. Protons and neutrons.
17. Splitting of a heavy nucleus.
18. One danger of nuclear reactors is the breakdown of cooling systems to allow _______-down.
19. Emitted particle identical to helium nucleus.
20. Force of attraction between nearest neighbor nucleons.
23. Electron emitted when neutron changes into proton in nucleus.

1. The fuel for fusion reactions.
2. Combination of two nuclei into one.
4. A nuclear ____ controls fission chain reactions to produce usable energy.
6. Fusion reactions only occur at extremely high ____.
9. Nuclear bullets used in fission reactions
11. When electrical _____ between protons is greater than strong forces, the nucleus will be unstable.
15. Reaction occurring when neutrons produced in fission reaction strike other nuclei.
16. Atoms of the same element with different masses.
21. Emission with no mass or charge.
22. ____ nuclei, with mass numbers over 82, are always unstable.