| A | B |
|---|
| Periodic Table | A chart of the elements showing the repeating pattern of their properties. |
| Nucleus | The central core of an atom containing protons and usually neutrons. |
| Proton | A small positively charged particle found in the nucleus of the atom (p). |
| Neutron | A small neutral particle found in the nucleus of the atom (n). |
| Electron | A tiny negatively charged particle found outside the nucleus or orbits or shells (e-). |
| Atomic Number | The number of protons in the nucleus of an atom (p = e-). |
| Atomic Mass | The number of protons plus neutrons found in the nucleus of the atom (p+n). |
| Electron Shell | Orbits or shells surrounding the nucleus of an atom that contain electrons (2, 8, 8). |
| Group | Elements in the same vertical column of the periodic table, also called family. |
| Period | A horizontal row of elements in the periodic table. |
| Valance Electrons | One of the electrons farthest away from the nucleus of the atom; these electrons are involved in a chemical reaction. |
| Conductor | A substance that transmits heat or electricity easily. |
| Insulator | A substance that resists the flow of heat or electricity. |
