Chemical element List of the 118 known chemical elements List of the 118 known chemical elements

| Atomic_no_ | Name_ | Symbol | Group_ | Period | Block | State_at_STP | Occurrence | Description_ |
|---|---|---|---|---|---|---|---|---|
| 11 | Sodium | Na | 1 | 3 | s | Solid | Primordial | Alkali metal |
| 12 | Magnesium | Mg | 2 | 3 | s | Solid | Primordial | Alkaline earth metal |
| 13 | Aluminium | Al | 13 | 3 | p | Solid | Primordial | Metal |
| 14 | Silicon | Si | 14 | 3 | p | Solid | Primordial | Metalloid |
| 15 | Phosphorus | P | 15 | 3 | p | Solid | Primordial | Non-metal |
| 16 | Sulfur | S | 16 | 3 | p | Solid | Primordial | Non-metal |
| 17 | Chlorine | Cl | 17 | 3 | p | Gas | Primordial | Halogen |
| 18 | Argon | Ar | 18 | 3 | p | Gas | Primordial | Noble gas |
| 19 | Potassium | K | 1 | 4 | s | Solid | Primordial | Alkali metal |
| 20 | Calcium | Ca | 2 | 4 | s | Solid | Primordial | Alkaline earth metal |
| 21 | Scandium | Sc | 3 | 4 | d | Solid | Primordial | Transition metal |