Beryllium vs Erbium
| Property | Be Beryllium | Er Erbium |
|---|---|---|
| Atomic number | 4 | 68 |
| Symbol | Be | Er |
| Name | Beryllium | Erbium |
| Category | alkaline-earth-metal | lanthanide |
| Standard Atomic Weight | 9.012183 u | 167.259 u |
| Period | 2 | 6 |
| Group | 2 | N/A |
| Block | s | s |
| Phase at STP | solid | solid |
| Electron configuration | [He]2s2 | [Xe]6s24f12 |
| Oxidation states | [0, 1, 2] | [0, 1, 2, 3] |
| Electronegativity (Pauling) | 1.57 | 1.24 |
| Electron affinity | -0.52 eV | 0.312 eV |
| Density | 1850 kg/m³ | 9070 kg/m³ |
| Melting point | 1286.85 °C | 1528.85 °C |
| Boiling point | 2470.85 °C | 2867.85 °C |
| Discovery year | 1797 | 1843 |