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72
Hf
178.49
Hafnium |
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): solid | |
| 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 6 M HCl: none | Reaction with 6 M HCl: none |
| Reaction with 15 M HNO3: passivated | Reaction with 6 M 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 |
