Template:Infobox hafnium

Hafnium, ₇₂Hf

Hafnium
Pronunciation	/ˈhæfniəm/ ​(HAF-nee-əm)
Appearance	steel gray
Standard atomic weight Ar, std(Hf)	178.486(6)
Hafnium in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Zr ↑ Hf ↓ Rf lutetium ← hafnium → tantalum
Atomic number (Z)	72
Group	group 4
Period	period 6
Block	d-block
Element category	d-block
Electron configuration	[Xe] 4f14 5d2 6s2
Electrons per shell	2, 8, 18, 32, 10, 2
Physical properties
Phase at STP	solid
Melting point	2506 K ​(2233 °C, ​4051 °F)
Boiling point	4876 K ​(4603 °C, ​8317 °F)
Density (near r.t.)	13.31 g/cm3
when liquid (at m.p.)	12 g/cm3
Heat of fusion	27.2 kJ/mol
Heat of vaporization	648 kJ/mol
Molar heat capacity	25.73 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 2689 2954 3277 3679 4194 4876
Atomic properties
Oxidation states	−2, 0, +1, +2, +3, +4 (an amphoteric oxide)
Electronegativity	Pauling scale: 1.3
Ionization energies	1st: 658.5 kJ/mol 2nd: 1440 kJ/mol 3rd: 2250 kJ/mol
Atomic radius	empirical: 159 pm
Covalent radius	175±10 pm
Spectral lines of hafnium
Other properties
Natural occurrence	primordial
Crystal structure	​hexagonal close-packed (hcp)
Speed of sound thin rod	3010 m/s (at 20 °C)
Thermal expansion	5.9 µm/(m·K) (at 25 °C)
Thermal conductivity	23.0 W/(m·K)
Electrical resistivity	331 nΩ·m (at 20 °C)
Magnetic ordering	paramagnetic
Magnetic susceptibility	+75.0·10−6 cm3/mol (at 298 K)
Young's modulus	78 GPa
Shear modulus	30 GPa
Bulk modulus	110 GPa
Poisson ratio	0.37
Mohs hardness	5.5
Vickers hardness	1520–2060 MPa
Brinell hardness	1450–2100 MPa
CAS Number	7440-58-6
History
Naming	after Hafnia. Latin for: Copenhagen, where it was discovered
Prediction	Dmitri Mendeleev (1869)
Discovery and first isolation	Dirk Coster and George de Hevesy (1922)
Main isotopes of hafnium
Iso­tope Abun­dance Physics:Half-life (t1/2) Decay mode Pro­duct 172Hf syn 1.87 y ε 172Lu 174Hf 0.16% 2×1015 y α 170Yb 176Hf 5.26% stable 177Hf 18.60% stable 178Hf 27.28% stable 178m2Hf syn 31 y IT 178Hf 179Hf 13.62% stable 180Hf 35.08% stable 182Hf syn 8.9×106 y β− 182Ta

Hf data m.p. cat
	in	calc from C	diff	report	ref
C	2233	—	—
K	2506	2506	0
F	4051	4051	0
max precision	0
WD
input	C: 2233, K: 2506, F: 4051
comment

Hf data b.p. cat
	in	calc from C	diff	report	ref
C	4603	—	—
K	4876	4876	0
F	8317	8317	0
max precision	0
WD
input	C: 4603, K: 4876, F: 8317
comment

PTChemistry:hafnium

Lu ← i'box Lu	iso72Hf  infobox  isobox	→ Ta i'box Ta
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Name and identifiers
Top image (caption, alt)
Pronunciation
Category (enwiki)
Standard atomic weight
most stable isotope
Natural occurrence
Phase at STP
Chemistry:Oxidation states
Spectral lines image
Physics:Electron configuration (cmt, ref)
Term symbol * (cmt, ref)
Wikidata *
* Not used in {{Infobox element}} (2019-02-03) See also {{Infobox element/symbol-to--navbox}}

References

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