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10203040506070809010011000.511.522.53‌ Å

93 - Neptunium actinide

Atomic Mass (u)

237

Density (g/cm³)

20.45

Phase

Solid

Year of Discovery

1940
NeptuniumNpElectron 1Electron 2Electron 1Electron 2Electron 3Electron 4Electron 5Electron 6Electron 7Electron 8Electron 1Electron 2Electron 3Electron 4Electron 5Electron 6Electron 7Electron 8Electron 9Electron 10Electron 11Electron 12Electron 13Electron 14Electron 15Electron 16Electron 17Electron 18Electron 1Electron 2Electron 3Electron 4Electron 5Electron 6Electron 7Electron 8Electron 9Electron 10Electron 11Electron 12Electron 13Electron 14Electron 15Electron 16Electron 17Electron 18Electron 19Electron 20Electron 21Electron 22Electron 23Electron 24Electron 25Electron 26Electron 27Electron 28Electron 29Electron 30Electron 31Electron 32Electron 1Electron 2Electron 3Electron 4Electron 5Electron 6Electron 7Electron 8Electron 9Electron 10Electron 11Electron 12Electron 13Electron 14Electron 15Electron 16Electron 17Electron 18Electron 19Electron 20Electron 21Electron 22Electron 1Electron 2Electron 3Electron 4Electron 5Electron 6Electron 7Electron 8Electron 9Electron 1Electron 2

Neptunium is a chemical element with symbol Np and atomic number 93. A radioactive actinide metal, neptunium is the first transuranic element. Its position in the periodic table just after uranium, named after the planet Uranus, led to it being named after Neptune, the next planet beyond Uranus.

93 Atomic Number
237  u Atomic Mass
913.15  K Melting Point
4273  K Boiling Point
20.45  g/cm³ Density
null  Å Atomic Radius
1.9  Å Covalent Radius
1.36 Electronegativity
6.27  eV First Ionization Energy
45.85 Electron Affinity
7 Number of Shells
2, 8, 18, 32, 22, 9, 2 Electron Shell Occupations
null  J/g Specific Heat