Selenium

Symbol

Se

Atomic number

34

Atomic mass	78.96		Thermal conductivity	0.0204
Atomic radius	1.22		Covalent radius	1.16
Density	4.80		Atomic volume	16.45
Melting point	490		Oxidation states	-2,4,6
Boiling point	958		Stable isotopes	5
Heat of vapor.	37.7		Electronegativity	2.55
Heat of fusion	6.694		First ionization	9.752
Specific heat	0.32		Electrical conduct.	...

Electron configuration

Selenium

Selenium occurs as a gray material and as a red allotropic material. The gray material has a small electrical conductivity in the dark which increases dramatically with exposure to light. This property is used in "selenium cells" for light sensors for control applications.

Selenium is used to impart a ruby-red color to glass and to neutralize the green color in glass which is present due to iron content.

Selenium is similar to sulfur in its chemical properties. One mineral form of selenium is the compound with lead, clausthalite, PbSe.

Selenium Nuclear Data