69 Tm

Thulium

Lanthanide
Atomic number69
CategoryLanthanide
Atomic mass168.93
Electron configuration[Xe]4f¹³ 6s²
Oxidation states+3
Electronegativity1.25
Melting point1,545 °C
Boiling point1,950 °C
Density9.32 g/cm³
Crystal structureClose-packed hexagonal
Period6
Blockf
Discovered1,879
Crustal abundance0.52 ppm

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