Selenium,Se

Properties

• Name: Selenium
• Atomic Number: 34
• Chemical Symbol: Se
• Electronic Configuration: [Ar]3d¹⁰4s²4p⁴
• Abundance:
  • Earth: 0.05 ppm
• Discovery: Jons Berzelius (1817)
• Ocurrence:
  • Berzeliante Cu₂Se
  • Naumannite Ag₂Se
  • Selenium Se
  • Tiemannite HgSe
  • Umangite Cu₃Se₂
• Most Common Elementary Substance : Se₈
• Elementary Substance Class : Non-metal
• Origin : Natural
• Physical State : Solid
• Density [298K] : 4790 kg m^-3
• Price : ~ 12.8 USD
• Cristal Lattice : hexagonal
• Melting Point : 490 K
• Boiling Point : 958 K
• Electrical Conductivity [298K] : 100 Ohm^-1m^-1
• Thermal Conductivity [300K] : 2.04 W m^-1K^-1
• Heat of:
  • Fusion: 5.1 kJ mol^-1
  • Vaporization: 26.32 kJ mol^-1
  • Atomization: 227 kJ mol^-1

Selenium is a rare element which has a very unpleasant smell. It is a grey solid at standard states.

Sources

Selenium occurs in the native state with sulfur in the form of seleniate in minerals such as eucairite (CuAgSe), claustalite (PbSe), naumanite (Ag2Se), crookesite ((CuTlAg)2Se) and zorgite (PbCuSe). The main selenium sources are copper ores, from which it is recovered as a by-product in the processes of electrolytic refining. The largest world producers are the USA, Canada, Sweden, Belgium, Japan and Peru.

Uses

Selenium's most important electronic property is photocondutivity. It is used in producing photocells, rectifiers and photographic exposure meters. Also selenium and its compounds can be used in the processes of xerographic reproduction, in the glass industry (cadmium seleniate, to produce red-ruby color), as degasifier in the metallurgical industry, as vulcanizing agent, as oxidizer in some reactions and as a catalyst .

Return to homepage