Comparison of Thorium and Uranium

Attribute	Uranium ×	Thorium ×
Standard state	Solid	Solid
Electron configuration	[Rn]7s²5f³6d¹	[Rn]7s²6d²
Atomic mass (u)	238.0289	232.038
Electronegativity (pauling scale)	1.38	1.3
Oxidation states	+3 +4 +5 +6	+4
Ionization energy (eV)	6.194	6.08
Atomic radius (van der waals) (pm)	240	237
Boiling point (K)	4404	5061
Melting point (K)	1408	2023
Density (g/cm³)	18.95	11.72
Atomic number	92	90
Group name	Actinide	Actinide
Discovered (year)	1789	1828
Symbol	U	Th