Neptunium

20.2
237
[Rn] 5f46d17s2
237Np
7
f
93
2, 8, 18, 32, 22, 9, 2
604.548
Np
20.2
644°C, 1191°F, 917 K
3902°C, 7056°F, 4175 K
Edwin McMillan and Philip Abelson
1940
7439-99-8
22375
More Information
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Atomic Data

Atomic Radiues, Non-bonded (A): 2.39
Electron Affinity (kJ mol-1): Unknown
Covalent Radiues (A): 1.80
Electronegativity (Pauling Scale): 1.3
Ionisation Energies (kJ mol-1) 1st 2nd 3rd 4th 5th 6th 7th 8th
604.548 - - - - - - -

Oxidation States and Isotopes

Common oxidation states 1
Isotope Atomic Mass Natural Abundance Half Life Mode of Decay
236Np 236.047 - 1.55 x 105 y EC
- β-
236Np 237.048 - 2.14 x 106 y α
1 x 1018 y sf

Pressure and Temperature Data

Specific Heat Capacity: Unknown
Shear Modulus: Unknown
Young Modulus: Unknown
Bulk Modulus: Unknown
Pressure 400k Pressure 600k Pressure 800k Pressure 1000k Pressure 1200k Pressure 1400k Pressure 1600k Pressure 1800k Pressure 2000k Pressure 2200k Pressure 2400k
- - - - 3.31 x 10-9 1.63 x 10-6 0.000168 0.00604 0.105 1.06 Unknown