Electronic data		Thermal data		Steric data
Shells: 2,8,18,32,10,2 Orbitals: [Xe] 4f14 5d2 6s2 Electronegativity: 1.2, 1.3 1. Ionization potential: 6.8251 eV 2. Ionization potential: 14.925 eV 3. Ionization potential: 23.32 eV Oxidation states: 4 Electrical conductivity: 0.0312 10^6		Melting point: 2227 °C Boiling point: 4602 °C Specific heat: 0.14 J/gK Heat of fusion: 24.060 kJ/mol Heat of vaporization: 575.0 kJ/mol Thermal conductivity: 0.230 W/cmK		Atomic radius: 2.16 Å Ionic radius: 0.83 Å () Covalent radius: 1.44 Å Atomic volume: 13.6 cm³/mol Density (293 K): 13.2 g/cm³ Crystal structure: Hexagonal

Nuclide	Abundance [%]	Mass	Spin	Halflife	Decay mode	Decay tree
172Hf	0	172	0	1.87y	EC	View
174Hf	0.18	173.94	0	2.0E15y		View
175Hf	0	175	5/2	70d	EC	View
176Hf	5.2	175.941	0	--	stable	--
177Hf	18.5	176.943	7/2	--	stable	--
178Hf	27.14	177.944	0	--	stable	--
179Hf	13.75	178.946	9/2	--	stable	--
180Hf	35.24	179.947	0	--	stable	--
181Hf	0	181	1/2	42.4d	-	View
182Hf	0	182	0	9E06y	-	View

Legend

Name origin:	From Hafnia, the Latin name of Copenhagen.
Description:	Silvery, ductile metal.
Discovered by:	Dirk Coster, Georg von Hevesy
Year:	1923
Place:	Denmark
Sources:	Obtained from mineral zircon or baddeleyite.
Use(s):	Used in reactor control rods because of its ability to absorb neutrons.