Argon vs Thallium
| Property | Ar Argon | Tl Thallium |
|---|---|---|
| Atomic number | 18 | 81 |
| Symbol | Ar | Tl |
| Name | Argon | Thallium |
| Category | noble-gas | post-transition-metal |
| Standard Atomic Weight | 39.948 u | 204.3835 u |
| Period | 3 | 6 |
| Group | 18 | 13 |
| Block | p | p |
| Phase at STP | gas | solid |
| Electron configuration | [Ne]3s23p6 | [Xe]6s24f145d106p1 |
| Oxidation states | [0] | [-5, -2, -1, 1, 2, 3] |
| Electronegativity (Pauling) | N/A | 1.62 |
| Electron affinity | -1 eV | 0.377 eV |
| Density | 1.7837 kg/m³ | 1.180000e+4 kg/m³ |
| Melting point | -189.35 °C | 303.85 °C |
| Boiling point | -185.85 °C | 1472.85 °C |
| Discovery year | 1894 | 1861 |