| A | B |
|---|
| alpha decay | radioactive decay that results in an alpha particle ( a helium nucleus) being emitted from the nucleus of a radioactive element. |
| alpha particle | positively charged particle emitted from the nucleus of an atom during radioactive decay; a helium nucleus. |
| beta decay | radioactive decay that results in a beta particle ( an electron) emitted from the nucleus of a radioactive element. |
| beta particles | a negatively charged particle (an electron) emitted from the nucleus of an atom during radioactive decay. |
| carbon dating | a technique to find out how old something is; the measure of carbon-14 in a sample that is between a few thousand and 50,000 years old. |
| emissions | the airborne gases and particles expelled through an operating automobile. |
| fossil fuels | hydrocarbon substances including oil, coal, and natural gas that are extracted from the Earth; the primary source of energy in the U.S. |
| fusion | a nuclear reaction that involves fusing nuclei from two atoms to make a different atom. |
| global warming | an increase in the Earth's temperature due to increased carbon dioxide in the atmosphere. |
| half-life | the length of time it takes for half an amount of radioactive substance to undergo radioactive decay. |
| isotope | forms of the same element that have different numbers of neutrons and different mass numbers. |
| nuclear reactions | a reaction that involves splitting the nucleus of an atom of fusing two nuclei; these reactions produce much more energy than chemical reactions. |
| nucleons | the protons and neutrons in the nucleus of an atom |
| photosynthesis | a chemical reaction performed by plants in which energy from the sun is converted to chemical energy; carbon dioxide is converted to sugar in this reaction. |
| radioactive | a term used to describe an atomic state when the nucleus is emitting radiation in the form of particles and energy until it becomes more stable. |
| fission | a nuclear reaction that involves the splitting of the nucleus of an atom. |
| radioactive isotope | an unstable isotope of an element that spontaniously undergoes radioactivite decay. |
| stable | a non-radioactive nucleus |
| unstable | a radioactive nucleus |
| gamma decay | the release of high-energy, electromagnetic radiation from the nucleus of radioactive (unstable) element. |
