Neptunium (93)

And now for something completely different ;') The synthetic elements!
Starting with the sea god's element: Neptunium!


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.


•Name: Neptunium
•Symbol: Np
•Atomic number: 93
•Atomic weight: [ 237 ] 
•Standard state: solid at 298 K
•CAS Registry ID: 7439-99-8
•Group in periodic table: 
•Group name: Actinoid
•Period in periodic table: 7 (actinoid)
•Block in periodic table: f-block
•Color: silvery metallic
•Classification: Metallic


Historical information
Neptunium was discovered by Edwin M. McMillan and P. H. Abelson at 1940 in USA, at Berkeley, California, who bombarded uranium with neutrons produced from a cyclotron.. Named after the planet Neptune, neptunium was the first synthetic transuranium element of the actinide series. It was discovered by McMillan and Abelson in 1940 It was the first synthetic transuranium (elements after uranium) element discovered.


Physical properties 
•Melting point: 910 [or 637 °C (1179 °F)] K
•Boiling point: 4300 [or ca. 4000 °C (7232 °F)] K
•Density of solid: 20450 kg m-3


Orbital properties
•Ground state electron configuration: [Rn].5f4.6d1.7s2
•Shell structure: 2.8.18.32.22.9.2
•Term symbol: 6L11/2