| Symbol |
Np |
|
| Atomic Number |
93 |
Relative Atomic Mass
12C = 12.0000 |
237.0482 |
Atomic Radius
pm |
150 |
First Ionisation Energy
kJ mol-1 |
597 |
| Electronegativity |
1.36 |
Density
kg m-3 |
20250 [293 K] |
Molar Volume
cm3 |
11.71 |
Thermal Conductivity
W m-1 K-1 |
6.3 [300 K] |
Melting Point
K |
913 |
Boiling Point
K |
4175 |
| Number of Isotopes |
21 |
Ground State Electron
Configuration |
[Rn]5f46d17s2 |
| Term Symbol |
6L11/2 |
| Discovery |
E. McMillan and P.H. Abelson (Berkeley, USA) in 1940 |
| Name Derived From |
Named after the planet Neptune |
Name in Other
Languages |
 Croatian | Neptunij |
 Danish | neptunium |
 Dutch | neptunium |
 Finnish | neptunium |
 French | neptunium |
 German | Neptunium |
 Italian | nettunio |
 Norwegian | neptunium |
 Portuguese | neptúnio |
 Spanish | neptunio |
 Swedish | neptunium |
| Peter van der Krogt's Element Multidict - element name translations in over 48 langauges |
