Atomic Element Z = 88 • Alkaline Earth Metal
Radium (Ra) — Atomic Data, Electron Shells & Reactions
Radium (symbol Ra, atomic number 88) has a standard atomic weight of 226 u and ground-state configuration [Rn] 7s2.
Atomic Number (Z)
88
IUPAC Symbol
Ra
Standard Atomic Weight
226 g/mol
Period / Group / Block
7 / 2 / s-block
Condensed Electron Config
[Rn] 7s2
Full Subshell Config
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 7s2
Principal Shell Occupancy
[2, 8, 18, 32, 18, 8, 2]
Pauling Electronegativity
0.9
First Ionization Energy
509 kJ/mol
Covalent Radius
221 pm
Melting Point
973 K (699.85 °C)
Boiling Point
2010 K (1736.85 °C)
Density
5.5 g/cm³
Oxidation States
+2
Ra (Z=88) — Valence shell highlighted in vermilion