« back
SeleniumSe Electron 1 Electron 2 Electron 1 Electron 2 Electron 3 Electron 4 Electron 5 Electron 6 Electron 7 Electron 8 Electron 1 Electron 2 Electron 3 Electron 4 Electron 5 Electron 6 Electron 7 Electron 8 Electron 9 Electron 10 Electron 11 Electron 12 Electron 13 Electron 14 Electron 15 Electron 16 Electron 17 Electron 18 Electron 1 Electron 2 Electron 3 Electron 4 Electron 5 Electron 6

Selenium is a chemical element with symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between those of its periodic table column-adjacent chalcogen elements sulfur and tellurium. It rarely occurs in its elemental state in nature, or as pure ore compounds.

34 Atomic Number
78.97  u Atomic Mass
494.15  K Melting Point
958  K Boiling Point
4.81  g/cm³ Density
1.2  Å Atomic Radius
1.2  Å Covalent Radius
2.55 Electronegativity
9.75  eV First Ionization Energy
194.96 Electron Affinity
4 Number of Shells
6 Electron Valency
2, 8, 18, 6 Electron Shell Occupations
0.32  J/g Specific Heat