Comparison of Boron and Hafnium

Attribute	Hafnium ×	Boron ×
Atomic mass (u)	178.49	10.81
Standard state	Solid	Solid
Oxidation states	+4	+3
Electron configuration	[Xe]6s²4f¹⁴5d²	[He]2s²2p¹
Atomic radius (van der waals) (pm)	212	192
Electronegativity (pauling scale)	1.3	2.04
Electron affinity (eV)	-	0.277
Ionization energy (eV)	6.825	8.298
Boiling point (K)	4876	4273
Melting point (K)	2506	2348
Density (g/cm³)	13.3	2.37
Atomic number	72	5
Group name	Transition metal	Metalloid
Symbol	Hf	B
Discovered (year)	1923	1808