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Astronomy Chemical element

Iridium

Iridium (Ir) is a chemical element belonging to the category transition metal, with atomic number 77 and standard atomic mass 192.2200 u. This sheet describes its fundamental properties, periodic position and physical characteristics.

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Astronomy · Chemical element

Iridium

EL25

Identity

  • Name: Iridium
  • Symbol: Ir
  • Atomic number: 77
  • Atomic mass: 192.2200 u

Position in the periodic table

  • Group: 9
  • Period: 6
  • Category: Transition metal (platinum group)

Physico-chemical properties

  • Standard state: Solid
  • Melting point: 2446°C
  • Density: 22.56 g/cm³ (20°C)
  • Electron configuration: [Xe] 4f¹⁴ 5d⁷ 6s²

Scientific description

Iridium is a chemical element with symbol Ir and atomic number 77. It is a very dense, corrosion-resistant transition metal of the platinum group, occupying group 9 and period 6 of the periodic table. Its standard atomic mass is approximately 192.2200 u and its density is among the highest of all known elements.