Comparison of Mendelevium and Nobelium

Attribute	Nobelium ×	Mendelevium ×
Atomic mass (u)	259.101	258.09843
Standard state	Solid	Solid
Oxidation states	+2 +3	+2 +3
Electron configuration	[Rn]7s²5f¹⁴	[Rn]7s²5f¹³
Ionization energy (eV)	6.65	6.58
Electronegativity (pauling scale)	1.3	1.3
Melting point (K)	1100	1100
Atomic number	102	101
Group name	Actinide	Actinide
Discovered (year)	1957	1955
^1↓Symbol	No	Md