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Name, Symbol, NumberNeptunium, Np, 93
Chemical series Actinides
Group, Period, Block_ [?], 7 , f
Density, Hardness 20250 kg/m3, n/a
Appearance silvery
Atomic Properties
Atomic weight 237.0482 amu
Atomic radius (calc.) n/a (n/a) pm
Covalent radius n/a pm
van der Waals radius n/a pm
Electron configuration [Rn]7s25f46d1
e- 's per energy level _
Oxidation states (Oxide) _
Crystal structure 3 forms: orthorhombic, tetragonal and cubic
Physical Properties
State of matter solid (__)
Melting point _ K (_ F)
Boiling point _ K (_ F)
Molar volume _ ×10-3 m3/mol
Heat of vaporization n/a kJ/mol
Heat of fusion _ kJ/mol
Vapor pressure unknown Pa at 1323 K
Velocity of sound unknown m/s at 293.15 K
Electronegativity _ (Pauling scale)
Specific heat capacity unknown J/(kg*K)
Electrical conductivity unknown 106/m ohm
Thermal conductivity _ W/(m*K)
1st ionization potential _ kJ/mol
2nd ionization potential _ kJ/mol
3rd ionization potential unknown kJ/mol
4th ionization potential unknown kJ/mol
Most Stable Isotopes
isoNAhalf-life DMDE MeVDP
237Np{syn.}2.14 106 years ___
SI units & STP are used except where noted.
Neptunium, also known less commonly as poseidonium, is a chemical element, in the periodic table that has the symbol Np and atom number 93.

External Link Los Alamos National Laboratory's Chemistry Division: Periodic Table - Neptunium


See: Periodic Table

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