Beryllium vs Neptunium

PropertyBe BerylliumNp Neptunium
Atomic number493
SymbolBeNp
NameBerylliumNeptunium
Categoryalkaline-earth-metalactinide
Standard Atomic Weight9.012183 u237 u
Period27
Group2N/A
Blockss
Phase at STPsolidsolid
Electron configuration[He]2s2[Rn]7s25f46d1
Oxidation states[0, 1, 2][2, 3, 4, 5, 6, 7]
Electronegativity (Pauling)1.571.36
Electron affinity-0.52 eV0.48 eV
Density1850 kg/m³2.025000e+4 kg/m³
Melting point1286.85 °C643.85 °C
Boiling point2470.85 °C3901.85 °C
Discovery year17971940