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Hafnium

72
Hf
178.49
Hafnium
 General | States | Energies | Oxidation & Electrons | Appearance & Characteristics | Reactions | Other Forms Radius | Conductivity | Abundance

General:

Name: Hafnium Symbol: Hf
Group: Trans. Met. Atomic weight: 178.49
Density @ 293 K: 13.2 g/cm3 Atomic volume: 13.6 cm3/mol
Group: Trans. Met. discovered: 1923

States:

state (s, l, g): s
melting point: 2495.2 K boiling point: 4723 K
Heat of fusion: 24.060 kJ/mol Heat of vaporization: 575.0 kJ/mol

Energies:

1st ionization energy: 680 kJ/mole
electronegativity: 1.3 2nd ionization energy: 1440 kJ/mole
electron affinity: 0 kJ/mole 3rd ionization energy: 2250 kJ/mole
Specific heat: 0.14 J/gK heat atomization: 619 kJ/mole atoms

Oxidation & Electrons:

Shells: 2,8,18,32,10,2 electron configuration: [Xe] 4f14 5d2 6s2
minimum oxidation number: 0 maximum oxidation number: 4
min. common oxidation no.: 0 max. common oxidation no.: 4

Appearance & Characteristics:

structure: hcp: hexagonal close pkd color: silvery
uses: nuclear control rods toxicity:
hardness: mohs characteristics: hard

Reactions:

reaction with air: mild, w/ht, =>HfO2
reaction with 6M HCl: none reaction with 6M HCl: none
reaction with 15M HNO3: passivated reaction with 6M NaOH: none

Other Forms:

number of isotopes: 6 hydride(s): HfH2
oxide(s): HfO2 chloride(s): HfCl3 HfCl4

Radius:

ionic radius (2- ion): pm ionic radius (1- ion): pm
atomic radius: 159 pm ionic radius (1+ ion): pm
ionic radius (2+ ion): pm ionic radius (3+ ion): pm

Conductivity:

thermal conductivity: 23.2 J/m-sec-deg
electrical conductivity: 28.49 1/mohm-cm polarizability: 16.2 A^3

Abundance:

source: Zircon (silicate)
rel. abund. solar system: -0.812 log abundance earth's crust: 0.4 log
cost, pure: 120 $/100g cost, bulk: $/100g