Atomic number: 24

Symbol: Cr

Category: transition metal

Density at 25°C: solid  7.19 g·cm−3

Chromium is most known for it's very shiny appearance. It is also very hard and corrosion resistant making it good for surface applications. It is most well known for chrome plating. A small amount of chromium was used in the first laser produced.

Chromium crystals and cube. image adapted from wikipedia

Use, natural applications or common combinations: 

  • Dyes and pigments
  • Catalysts, first laser, synthetic ruby laser
  • commercially viable in ore as chromite, which is iron chromium oxide (FeCr2O4)

Basic characteristics:

  • Standard atomic weight: 51.9961(6)
  • Melting point: 1907 °C
  • Boiling point: 2671 °C
  • Radioactivity:  almost all stable naturally