34

Se

Selenium
78.96 (3)
 Historical Information

Selenium (Gr. Selen, moon) was discovered by Jöns Jacob Berzelius in 1817. He reported that tellurium was present in sulphuric acid from a Swedish factory, but in the following year decided that the impurity was not tellurium but another closely related element that he subsequently identified as selenium.
Basic Information Shells
  • Name:Selenium
  • Symbol: Se
  • Atomic number: 34
  • Atomic weight:78.96 (3)
  • Standard state: solid at 298 K
  • Group in periodic table: 16
  • Group name: Chalcogen
  • Period in periodic table: 4
  • Block in periodic table: p-block
  • Classification: Non-metallic
 Selenium
Uses Trivia
  • photographic toner
  • additive for stainless steel

Selenium occurs in some soils in amounts sufficient to produce serious effects on animals feeding on plants such as locoweed (an American plant) grown in such soils.