Comparison of Strontium and Radium

Attribute	Radium ×	Strontium ×
Standard state	Solid	Solid
Electron configuration	[Rn]7s²	[Kr]5s²
Atomic mass (u)	226.02541	87.62
Electronegativity (pauling scale)	0.9	0.95
Oxidation states	+2	+2
Ionization energy (eV)	5.279	5.695
Atomic radius (van der waals) (pm)	283	249
Boiling point (K)	1413	1655
Melting point (K)	973	1050
Density (g/cm³)	5	2.64
Atomic number	88	38
Group name	Alkaline earth metal	Alkaline earth metal
Discovered (year)	1898	1790
Symbol	Ra	Sr