Thulium (Tm) — Atomic Data, Electron Shells & Reactions

Atomic Number (Z) 69 IUPAC Symbol Tm Standard Atomic Weight 168.93 g/mol Period / Group / Block 6 / f-block / f-block Condensed Electron Config [Xe] 4f13 6s2 Full Subshell Config 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f13 5s2 5p6 6s2 Principal Shell Occupancy [2, 8, 18, 31, 8, 2] Pauling Electronegativity 1.25 First Ionization Energy 597 kJ/mol Covalent Radius 190 pm Melting Point 1818 K (1544.85 °C) Boiling Point 2223 K (1949.85 °C) Density 9.321 g/cm³ Oxidation States +3