Neptunium

Kemiallinen merkki: Np
Järjestysluku: 93
Kategoria: aktinoidit
Ryhmä: n/a
Jakso: 7
Lohko: f
Moolimassa: (237) g/mol
Elektronia kuorilla: 2, 8, 18, 32, 22, 9, 2
CAS-numero: 7439-99-8
Olomuoto: kiinteä
Tiheys: 20,45 kg/l (lähellä huoneenlämpöä)
Sulamispiste: 910 K (637 °C, 1179 °F)
Kiehumispiste: 4273 K (4000 °C, 7232 °F)
Kiderakenne: orthorhombic, tetragonal and cubic
Hapetusluvut: 3, 4, 5, 6
Elektronegatiivisuus: 1,36 (Pauling-asteikko)
Nimen alkuperä: Neptunus
Nimen tarkoitus: the planet in the Solar System
Faktoja:
- is silvery in color
- is found in three allotropes: alpha-, beta- and gamma-neptunium
- is fissionable, and could theoretically be used as fuel in a fast neutron reactor or a nuclear weapon
- is also used in neutron detection devices
- trace amounts of neptunium are found naturally as decay products from transmutation reactions in uranium ores
- due to its long half life neptunium becomes the major contributor of the total radiation in 10000 years
- is fairly reactive chemically