88
Ra
226
Radium
Element 88 · 226 u · s-block
alkaline earth
A highly radioactive element discovered by Pierre and Marie Curie. Once used in luminous watch dials with tragic consequences.
Phase (STP)
Solid
Melting Point
700 °C
Boiling Point
1737 °C
Density
5.5 g/cm³
Electronegativity
0.9
Atomic Radius
215 pm
Ionization Energy
509 kJ/mol
Electron Affinity
10 kJ/mol
Discovered
1898 · Marie Curie
Electron Configuration
[Rn] 7s2
Electron Orbitals
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