In detail

Neptunium (Np) properties


Atomic mass, symbol and atomic number

neptunium is an artificially created element with the element symbol Np and atomic number 93. In the periodic table it belongs to the actinoids with an atomic mass of 237.048 u. The chemical element discovered by E. McMillan and P. Abelson in 1940 is radioactive and is in a solid state at room temperature.

Profile: Neptunium (English Neptunium)

General
Chemical element:neptunium
Symbol:np
Atomic number:93
Group:actinides
Period:7
Block:f-block
Series:actinides
Appearance:silver
explorers:Edwin McMillan and Philip Abelson
Year of discovery:1940
Atomic properties
Atomic mass:237.048 u
Atomic radius:155 pm
Covalent radius:190 pm
Van der Waals radius:unknown
Electron configuration:Rn 5f4 6d1 7s2
ionization:604.5 kJ / mol
Physical Properties
Physical state:firmly
Density:20.45 g / cm3
Crystal structure:orthorhombisch
Magnetism:unknown
molar volume:11,59 · 10-6 m3/ mol
Mohs hardness:???
Melting point:639 ° C
Boiling point:3902 ° C
Heat of fusion:39 kJ / mol
Heat of vaporization:1420 kJ / mol
Thermal conductivity:6 W
Chemical properties
electronegativity:1,36

Did you know that ...

  • the element Neptunium was named after the planet Neptune?
  • Neptunium dependent on the oxidation state in different colors (black, red, yellow and green) occurs?
  • the once naturally occurring neptunium on earth has long since disintegrated, and because of this it only occurs artificially synthesized?