Comparison of Neodymium and Actinium

Attribute	Actinium ×	Neodymium ×
Standard state	Solid	Solid
Electron configuration	[Rn]7s²6d¹	[Xe]6s²4f⁴
Atomic mass (u)	227.02775	144.24
Electronegativity (pauling scale)	1.1	1.14
Oxidation states	+3	+3
Ionization energy (eV)	5.17	5.525
Atomic radius (van der waals) (pm)	260	229
Boiling point (K)	3471	3347
Melting point (K)	1324	1294
Density (g/cm³)	10.07	7.01
Atomic number	89	60
Group name	Actinide	Lanthanide
Discovered (year)	1899	1885
Symbol	Ac	Nd