Periodic table of the elements
FranciumRadiumActinium
88
Ra
Radium
(226)
2
8
18
32
18
8
2
88
Ra
Radium
(226)
2
8
18
32
18
8
2
General
NameRadium
SymbolRa
Number88
Chemical seriesAlkaline earth metals
Group / Period2 / 7
Blocks-block
CAS registry number7440-14-4

Radium is a radioactive element

Physical properties
Statesolid
Density5.5 g/cm3
Melting point973 K (700 °C, 1292 °F)
Boiling point2010 K (1737 °C, 3159 °F)
Critical point

Atomic properties
Atomic Weight(226) g/mol
Crystal structurecubic body centered
Electronegativity0.9
Atomic radius215 pm
Atomic radius (calculated)
Electron configuration[Rn] 7s2
Electrons per shell2, 8, 18, 32, 18, 8, 2
Number of protons88
Number of neutrons138

Other languages
SpanishRadio
PortugueseRádio
FrenchRadium
GermanRadium
ItalianRadio
RussianРадий
PolishRad
Chinese
Arabicراديوم
TurkishRadyum
DutchRadium


Periodic table of the elements
FranciumRadiumActinium