Comparison of Technetium and Hafnium

Attribute	Hafnium ×	Technetium ×
Atomic mass (u)	178.49	96.90636
Standard state	Solid	Solid
Oxidation states	+4	+4 +6 +7
Electron configuration	[Xe]6s²4f¹⁴5d²	[Kr]5s²4d⁵
Atomic radius (van der waals) (pm)	212	209
Electronegativity (pauling scale)	1.3	1.9
Electron affinity (eV)	-	0.55
Ionization energy (eV)	6.825	7.28
Boiling point (K)	4876	4538
Melting point (K)	2506	2430
Density (g/cm³)	13.3	11
Atomic number	72	43
Group name	Transition metal	Transition metal
Symbol	Hf	Tc
Discovered (year)	1923	1937