Chlorine vs Promethium
| Property | Cl Chlorine | Pm Promethium |
|---|---|---|
| Atomic number | 17 | 61 |
| Symbol | Cl | Pm |
| Name | Chlorine | Promethium |
| Category | halogen | lanthanide |
| Standard Atomic Weight | 35.4515 u | 145 u |
| Period | 3 | 6 |
| Group | 17 | N/A |
| Block | p | s |
| Phase at STP | gas | solid |
| Electron configuration | [Ne]3s23p5 | [Xe]6s24f5 |
| Oxidation states | [-1, 1, 2, 3, 4, 5, 6, 7] | [2, 3] |
| Electronegativity (Pauling) | 3.16 | N/A |
| Electron affinity | 3.6127 eV | 0.129 eV |
| Density | 3.214 kg/m³ | 7260 kg/m³ |
| Melting point | -101.5 °C | 1041.85 °C |
| Boiling point | -34.04 °C | 2999.85 °C |
| Discovery year | 1774 | 1902 |