93 Np

Neptunium

Actinide
Atomic number93
CategoryActinide
Atomic mass237
Electron configuration[Rn]5f⁴ 6d¹ 7s²
Oxidation states+5
Electronegativity1.36
Melting point644 °C
Boiling point3,902 °C
Density20.45 g/cm³
Crystal structureOrthorhombic
Period7
Blockf
Discovered1,940
Crustal abundance0 ppm

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