| 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 particles | a partially charged particle emitted from the nucleus of an atom during radioactive decay; also called a helium nucleus. |
| beta decay | radioactive decay that results in a beta particle (an electron) being 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’s tailpipe. |
| fission | a nuclear reaction that involves the splitting of the nucleus of an atom. |
| fossil fuels | hydrocarbon substances including oil, coal, and natural gas that are extracted from the Earth |
| 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 mainly to increased carbon dioxide and other heatabsorbing gases in the atmosphere. |
| half-life | the length of time it takes for half an amount of radioactive substance to undergo radioactive decay. |
| neutral | when one proton is paired with one electron |
| nuclear reactions | a reaction that involves splitting the nucleus of an atom or 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. |
| radiation | (1) the process of emitting radiant energy; (2) a term to describe the particles and energy that are emitted from radioactive substances. |
| radioactive | a term to describe an atomic state when the nucleus is emitting radiation in the form of particles and energy until it becomes more stable. |
| radioactive isotope | an unstable isotope of an element that spontaneously undergoes radioactive decay. |
| stable | (1) a term used to describe an atom that has a balance of charge; (2) a non-radioactive nucleus. |
| unstable | (1) a term used to describe an atom that has an unbalance of charge; (2) a radioactive nucleus. |
