Neptunium: the essentials
Neptunium is a radioactive rare earth metal and has at least 3 allotropic forms. It is named for the planet Neptune. Np-237 is a by-product from nuclear reactors.
Neptunium: historical information
Neptunium was the first synthetic transuranium element of the actinide series. It was discovered by McMillan and Abelson in 1940 at Berkeley, California, USA, who bombarded uranium with neutrons produced from a cyclotron. It was the first synthetic transuranium (elements after uranium) element discovered.
Neptunium around us Read more »
Neptunium has no biological role.
Trace amounts of neptunium are present in uranium ores. In practice, isolable amounts are best extracted from spent uranium fuel rods produced in nuclear reactors.
|Location||ppb by weight||ppb by atoms||Links|
|Universe||(no data)||(no data)|
|Crustal rocks||(no data)||(no data)|
|Human||(no data) ppb by weight||(no data) atoms relative to C = 1000000|
Physical properties Read more »
Heat properties Read more »
- Melting point: 910 [637 °C (1179 °F)] K
- Boiling point: 4300 [ca. 4000 °C (7232 °F)] K
- Enthalpy of fusion: |203| kJ mol-1
Crystal structure Read more »
The solid state structure of neptunium is: orthorhombic.
Neptunium: orbital properties Read more »
Neptunium atoms have 93 electrons and the shell structure is 184.108.40.206.22.9.2. The ground state electronic configuration of neutral Neptunium is [Rn].5f4.6d1.7s2 and the term symbol of Neptunium is 6L11/2.
- Pauling electronegativity: 1.36 (Pauling units)
- First ionisation energy: 604.5 kJ mol‑1
- Second ionisation energy: (no data) kJ mol‑1
Isolation: coming soon!
Neptunium isotopes Read more »