Comparison of Samarium and Europium

Attribute	Europium ×	Samarium ×
Standard state	Solid	Solid
Electron configuration	[Xe]6s²4f⁷	[Xe]6s²4f⁶
Atomic mass (u)	151.964	150.4
Electronegativity (pauling scale)	-	1.17
Oxidation states	+2 +3	+2 +3
Ionization energy (eV)	5.67	5.644
Atomic radius (van der waals) (pm)	233	229
Boiling point (K)	1802	2067
Melting point (K)	1095	1347
Density (g/cm³)	5.24	7.52
Atomic number	63	62
Group name	Lanthanide	Lanthanide
Symbol	Eu	Sm
Discovered (year)	1901	1879