Promethium (Pm) — Atomic Data, Electron Shells & Reactions

Atomic Number (Z) 61 IUPAC Symbol Pm Standard Atomic Weight 145 g/mol Period / Group / Block 6 / f-block / f-block Condensed Electron Config [Xe] 4f5 6s2 Full Subshell Config 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f5 5s2 5p6 6s2 Principal Shell Occupancy [2, 8, 18, 23, 8, 2] Pauling Electronegativity 1.13 First Ionization Energy 540 kJ/mol Covalent Radius 199 pm Melting Point 1315 K (1041.85 °C) Boiling Point 3273 K (2999.85 °C) Density 7.26 g/cm³ Oxidation States +3