Comparison of Germanium and Actinium

Attribute	Actinium ×	Germanium ×
Atomic mass (u)	227.02775	72.63
Standard state	Solid	Solid
Oxidation states	+3	+2 +4
Electron configuration	[Rn]7s²6d¹	[Ar]4s²3d¹⁰4p²
Atomic radius (van der waals) (pm)	260	211
Electronegativity (pauling scale)	1.1	2.01
Electron affinity (eV)	-	1.35
Ionization energy (eV)	5.17	7.9
Boiling point (K)	3471	3106
Melting point (K)	1324	1211.4
Density (g/cm³)	10.07	5.323
Atomic number	89	32
Group name	Actinide	Metalloid
Symbol	Ac	Ge
Discovered (year)	1899	1886