19K39.098
Potassium (K)
Element 19 Ā· Alkali metal
Potassium (K) is a chemical element with atomic number 19. It is classified as an alkali metal in period 4, group 1 of the periodic table (the s-block). Its standard atomic weight is 39.098 u and its ground-state electron configuration is [Ar] 4sĀ¹.
Potassium facts
| Atomic number (Z) | 19 |
|---|---|
| Symbol | K |
| Standard atomic weight | 39.098 u |
| Category | Alkali metal |
| Group | 1 |
| Period | 4 |
| Block | s-block |
| Electron configuration | [Ar] 4sĀ¹ |
| Electronegativity (Pauling) | 0.82 |
| State at 20 Ā°C | Solid |
| Protons / electrons | 19 / 19 |
| Neutrons (most common isotope, approx.) | 20 |
| Molar mass | 39.098 g/mol |