| A | B |
|---|
| Atomic number | tells us the number of protons in the atom |
| Atomic mass | tells us the number of protons and neutrons in the atom |
| Family or Groups | vertical columns on the periodic table |
| Period | horizontal columns on the periodic table |
| Alkali metals | most active metal group on the periodic table |
| Halogens | most active nonmetal groups on the periodic table |
| Metalloids | have properties of both metals and nonmetalas |
| Metals | good conductors of heat and electricity |
| Solid | tightly packed particles |
| Gas | particles very far apart because of high kinetic energy |
| Nonmetals | Poor conductors of heat and electricity |
| Element symbol | One or two letters used to represent the name of an element |
| Noble gases | a stable group of elements on the periodic table |
| Liquid | more loosely packed particles that take the shape of its container |
