Arsenic vs Erbium
| Property | As Arsenic | Er Erbium |
|---|---|---|
| Atomic number | 33 | 68 |
| Symbol | As | Er |
| Name | Arsenic | Erbium |
| Category | metalloid | lanthanide |
| Standard Atomic Weight | 74.921595 u | 167.259 u |
| Period | 4 | 6 |
| Group | 15 | N/A |
| Block | p | s |
| Phase at STP | solid | solid |
| Electron configuration | [Ar]4s23d104p3 | [Xe]6s24f12 |
| Oxidation states | [-3, -2, -1, 0, 1, 2, 3, 4, 5] | [0, 1, 2, 3] |
| Electronegativity (Pauling) | 2.18 | 1.24 |
| Electron affinity | 0.81 eV | 0.312 eV |
| Density | 5776 kg/m³ | 9070 kg/m³ |
| Melting point | 816.85 °C | 1528.85 °C |
| Boiling point | 613.85 °C | 2867.85 °C |
| Discovery year | 1250 | 1843 |