Potassium vs Calcium
| Property | K Potassium | Ca Calcium |
|---|---|---|
| Atomic number | 19 | 20 |
| Symbol | K | Ca |
| Name | Potassium | Calcium |
| Category | alkali-metal | alkaline-earth-metal |
| Standard Atomic Weight | 39.0983 u | 40.078 u |
| Period | 4 | 4 |
| Group | 1 | 2 |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [Ar]4s1 | [Ar]4s2 |
| Oxidation states | [-1, 1] | [1, 2] |
| Electronegativity (Pauling) | 0.82 | 1 |
| Electron affinity | 0.5014 eV | 0.0245 eV |
| Density | 890 kg/m³ | 1540 kg/m³ |
| Melting point | 63.38 °C | 841.85 °C |
| Boiling point | 758.85 °C | 1483.85 °C |
| Discovery year | 1807 | 1808 |