Key elements from the first three rows of the periodic table.
| Element | Symbol | Atomic Number | Atomic Mass (u) | Category |
|---|---|---|---|---|
| Hydrogen | H | 1 | 1.008 | nonmetal |
| Helium | He | 2 | 4.003 | noble gas |
| Lithium | Li | 3 | 6.941 | alkali metal |
| Carbon | C | 6 | 12.011 | nonmetal |
| Nitrogen | N | 7 | 14.007 | nonmetal |
| Oxygen | O | 8 | 15.999 | nonmetal |
| Neon | Ne | 10 | 20.18 | noble gas |
| Sodium | Na | 11 | 22.99 | alkali metal |