Argon vs Erbium
| Property | Ar Argon | Er Erbium |
|---|---|---|
| Atomic number | 18 | 68 |
| Symbol | Ar | Er |
| Name | Argon | Erbium |
| Category | noble-gas | lanthanide |
| Standard Atomic Weight | 39.948 u | 167.259 u |
| Period | 3 | 6 |
| Group | 18 | N/A |
| Block | p | s |
| Phase at STP | gas | solid |
| Electron configuration | [Ne]3s23p6 | [Xe]6s24f12 |
| Oxidation states | [0] | [0, 1, 2, 3] |
| Electronegativity (Pauling) | N/A | 1.24 |
| Electron affinity | -1 eV | 0.312 eV |
| Density | 1.7837 kg/m³ | 9070 kg/m³ |
| Melting point | -189.35 °C | 1528.85 °C |
| Boiling point | -185.85 °C | 2867.85 °C |
| Discovery year | 1894 | 1843 |