24Cr51.996
Chromium
Transition metalsHard, shiny metals that conduct heat and electricity well and often form coloured compounds.
[Ar] 3d⁵ 4s¹
- Atomic number
- 24
- Atomic mass
- 51.996
- Protons
- 24
- Neutrons
- 28 (most common)
- Electrons
- 24
- Shells
- 2, 8, 13, 1
- State at 25 °C
- Solid
- Position
- Group 6, period 4
Proton (+)Neutron (0)Electron (−)
Discovered byLouis-Nicolas Vauquelin, 1797Louis-Nicolas Vauquelin: 2 elements
Vauquelin found it in a bright red mineral. The name comes from the Greek chroma, meaning colour, because its compounds are so colourful.
Did you know?
- Stainless steel contains at least about 10.5% chromium.
- Chromium gives rubies their red and emeralds their green.
Where it's found
- Chromite ore, mined in Odisha
What it's used for
- Stainless steel
- Shiny chrome plating
Try it
Stainless vs plain ironSafe at home
- 1Put a stainless-steel spoon and a plain iron nail in a glass of salty water.
- 2Leave them for 3 days.
What you'll see: The nail rusts; the spoon stays shiny. Chromium forms a thin protective layer.