| A | B |
|---|
| Nitrogen fixation | The process of changing free nitrogen into a usable form of nitrogen. |
| Carbon/oxygen cycle | Producers, consumers and decomposers play a role in recycling this. |
| Nitrogen cycle | Nitrogen moves from the air to the soil, into living things, and back into the air. |
| Atomic number | The number of protons in the nucleus of an atom. |
| Atomic mass | The average mass of all the isotopes of an element. |
| Periodic table | A chart of the elements showing the repeating pattern of their properties. |
| Chemical symbol | A one or two letter representation of an element. |
| Period | A horizontal row of elements in the periodic table. |
| Group | Elements in the same vertical column of the periodic table; also called family. |
