Atomica
56Ba137.33

Barium

Alkaline earth metals

Reactive metals with two outer electrons, found in rocks, shells and bones.

[Xe] 6s²

Atomic number
56
Atomic mass
137.33
Protons
56
Neutrons
81 (most common)
Electrons
56
Shells
2, 8, 18, 18, 8, 2
State at 25 °C
Solid
Position
Group 2, period 6
Proton (+)Neutron (0)Electron (−)
Discovered byHumphry Davy, 1808Humphry Davy: 7 elementsCarl Wilhelm Scheele: 6 elements

Davy isolated it using electricity. The name comes from the Greek barys, meaning heavy, because its minerals are dense.

Did you know?

  • A barium sulfate drink shows up clearly on X-rays.
  • It gives fireworks their green colour.

Where it's found

  • Baryte mineral

What it's used for

  • Barium meals for X-ray scans of the gut
  • Green fireworks
  • Drilling mud for oil wells

Try it

There's no safe home experiment for Barium. Explore it with the animated atom above instead.