Across
- 7. each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.
- 8. the total number of protons and neutrons in a nucleus
- 9. atoms are split apart, which releases energy
- 10. a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus during the process of beta decay
- 11. an uncharged elementary particle that has a mass nearly equal to that of the proton and is present in all known atomic nuclei except the hydrogen nucleus.
- 12. the emission of ionizing radiation or particles caused by the spontaneous disintegration of atomic nuclei
- 13. cell that contains the chromosomes
- 14. the time taken for the radioactivity of a specified isotope to fall to half its original value
Down
- 1. a radiation hazard for the entire body
- 2. a chemical reaction or other process in which the products themselves promote or spread the reaction, which under certain conditions may accelerate dramatically.
- 3. a stable subatomic particle occurring in all atomic nuclei, with a positive electric charge equal in magnitude to that of an electron, but of opposite sign
- 4. the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table
- 5. composite particles consisting of two protons and two neutrons tightly bound together
- 6. the process by which two light atomic nuclei combine to form a single heavier one while releasing massive amounts of energy