Hafnium
Lát'ọwọ́ Wikipedia, ìwé ìmọ̀ ọ̀fẹ́
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| Ìfarahàn |
steel grey
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| Àwọn ìní àníkárí |
| Orúkọ, àmì-ìdámọ̀, nọ́mbà |
hafnium, Hf, 72 |
| Ìpè |
/ˈhæfniəm/, HAF-nee-əm |
| Ẹ̀ka apilẹ̀sẹ̀ |
transition metal |
| Àdìpọ̀, ìgbà, block |
4, 6, d |
| Ìwúwo átọ́mù |
178.49 g·mol−1 |
| Ìtòjọ ẹ̀lẹ́ktrónì |
[Xe] 4f14 5d2 6s2 |
| Àwọn ẹ̀lẹ́ktrónì lórí ọ̀nà kan |
2, 8, 18, 32, 10, 2 (Image) |
| Àwọn ìní aláfójúrí |
| Phase |
solid |
| Kíki (tó súnmọ́ r.t.) |
13.31 g·cm−3 |
| Liquid density at m.p. |
12 g·cm−3 |
| ojúàmì ìyọ́ |
2506 K, 2233 °C, 4051 °F |
| ajúàmì ìhó |
4876 K, 4603 °C, 8317 °F |
| Heat of fusion |
27.2 kJ·mol−1 |
| Heat of vaporization |
571 kJ·mol−1 |
| Specific heat capacity |
(25 °C) 25.73 J·mol−1·K−1 |
| Vapor pressure |
| P/Pa |
1 |
10 |
100 |
1 k |
10 k |
100 k |
| at T/K |
2689 |
2954 |
3277 |
3679 |
4194 |
4876 |
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| Atomic properties |
| Oxidation states |
4, 3, 2 (amphoteric oxide) |
| Electronegativity |
1.3 (Pauling scale) |
| Ionization energies |
1st: 658.5 kJ·mol−1 |
| 2nd: 1440 kJ·mol−1 |
| 3rd: 2250 kJ·mol−1 |
| Atomic radius |
159 pm |
| Covalent radius |
175±10 pm |
| Miscellanea |
| Crystal structure |
hexagonal |
| Magnetic ordering |
paramagnetic[1] |
| Electrical resistivity |
(20 °C) 331 nΩ·m |
| Thermal conductivity |
(300 K) 23.0 W·m−1·K−1 |
| Thermal expansion |
(25 °C) 5.9 µm·m−1·K−1 |
| Speed of sound (thin rod) |
(20 °C) 3010 m/s |
| Young's modulus |
78 GPa |
| Shear modulus |
30 GPa |
| Bulk modulus |
110 GPa |
| Poisson ratio |
0.37 |
| Mohs hardness |
5.5 |
| Vickers hardness |
1760 MPa |
| Brinell hardness |
1700 MPa |
| CAS registry number |
7440-58-6 |
| Most stable isotopes |
| Main article: Isotopes of hafnium |
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