Histoire & Art A transdisciplinary graph

Astronomy Chemical element

Selenium

Selenium (Se) is a chemical element belonging to the category Metalloid, with atomic number 34 and atomic mass 78.9710 u. This sheet describes its fundamental properties, periodic position and physical characteristics.

Stays within its layer Astronomy

Neighbourhood in the graph

Above, what contains it; below, what it contains; on the right, what links it to another layer.

Astronomy · Chemical element

Selenium

ELY

Identity

  • Name: Selenium
  • Symbol: Se
  • Atomic number: 34
  • Atomic mass: 78.9710 u

Position in the periodic table

  • Group: 16
  • Period: 4
  • Category: Metalloid

Physico-chemical properties

  • Standard state: Solid
  • Melting point: 221 °C
  • Boiling point: 685 °C
  • Density: 4.81 g/cm³
  • Electron configuration: [Ar] 3d¹⁰ 4s² 4p⁴

Scientific description

Selenium is a chemical element with symbol Se and atomic number 34. It belongs to the category of Metalloid and occupies group 16 and period 4. Its standard atomic mass is 78.9710 u.