| Ra | Radium | Atomic number : 88 Relative atomic mass (12C = 12.0000) : 226.0254 (Ra-226) |
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| P H Y S I C A L D A T A | |
| Group 2 alkaline earth metal Density / kg m-3 : c. 5000 [293 K] |
Melting point / K : 973 Boiling point / K : 1413 |
| D I S C O V E R Y | |
| Radium was discovered in 1898 by Pierre and Marie Curie at Paris, France. Isolated as the metal by Mme. Curie in 1911 by the electrolysis of RaCl2. |
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| G E O L O G I C A L D A T A | |
| Abundances Sun (relative to H = 1 × 1012) : n.a. Earth's crust / p.p.m. : 6 × 10-7 Oxidation state : II |
Seawater / p.p.m. : 2 × 10-11 |
| B I O L O G I C A L D A T A | |
| Level in humans Blood / mg dm-3 : 6.6 × 10-9 Bone / p.p.m. : 4 × 10-9 Liver / p.p.m. : 0.023 × 10-9 Muscle / p.p.m. : 0.23 × 10-9 |
Daily dietary intake : 2 × 10-9 mg Total mass of element in average (70 kg) person : 31 × 10-9 mg |
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A portrait of radium is available on the Visual Elements site. Up to 200 individual items of information on this element are available in The Elements. |