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87. Francium 89. Actinium

88Ra[226]

Radium

Alkaline earth metals

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

[Rn] 7s²

Atomic number: 88
Atomic mass: [226]
Protons: 88
Neutrons: 138
Electrons: 88
Shells: 2, 8, 18, 32, 18, 8, 2
State at 25 °C: Solid
Position: Group 2, period 7

Proton (+)Neutron (0)Electron (−)

Discovered byMarie and Pierre Curie, 1898Marie Curie: 2 elements Pierre Curie: 2 elements

The Curies processed tonnes of ore to isolate tiny amounts of radium. Marie Curie won two Nobel Prizes, in physics and chemistry.

Did you know?

It glows faintly blue in the dark.
Marie Curie's notebooks are still radioactive.

Where it's found

Uranium ores

What it's used for

Treating some bone cancers
Once used in glowing watch dials, now banned

Try it

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