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