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Zirconium |
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Pronunciation | (zur-KOH-nee-əm) |
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Appearance | sillery white |
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Standard atomic weight Ar, std(Zr) | 7001912240000000000♠91.224(2)[1] |
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Zirconium in the periodic cairt |
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Atomic nummer (Z) | 40 |
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Group | group 4 |
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Period | period 5 |
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Block | d-block |
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Element category | Transeetion metal |
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Electron confeeguration | [Kr] 4d2 5s2 |
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Electrons per shell | 2, 8, 18, 10, 2 |
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Pheesical properties |
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Phase at STP | solit |
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Meltin pynt | 2128 K (1855 °C, 3371 °F) |
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Bylin pynt | 4682 K (4409 °C, 7968 °F) |
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Density (near r.t.) | 6.52 g/cm3 |
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when liquid (at m.p.) | 5.8 g/cm3 |
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Heat o fusion | 14 kJ/mol |
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Heat o vapourisation | 573 kJ/mol |
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Molar heat capacity | 25.36 J/(mol·K) |
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Vapour pressur
P (Pa) |
1 |
10 |
100 |
1 k |
10 k |
100 k |
at T (K) |
2639 |
2891 |
3197 |
3575 |
4053 |
4678 |
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Atomic properties |
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Oxidation states | −2, +1,[2] +2, +3, +4 (an amphoteric oxide) |
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Electronegativity | Pauling scale: 1.33 |
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Atomic radius | empirical: 160 pm |
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Covalent radius | 175±7 pm |
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Spectral lines o zirconium |
Ither properties |
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Naitural occurrence | primordial |
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Creestal structur | hexagonal close-packed (hcp) |
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Speed o soond thin rod | 3800 m/s (at 20 °C) |
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Thermal expansion | 5.7 µm/(m·K) (at 25 °C) |
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Thermal conductivity | 22.6 W/(m·K) |
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Electrical resistivity | 421 n Ω·m (at 20 °C) |
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Magnetic orderin | paramagnetic[3] |
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Young's modulus | 88 GPa |
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Shear modulus | 33 GPa |
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Bulk modulus | 91.1 GPa |
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Poisson ratio | 0.34 |
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Mohs haurdness | 5.0 |
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Vickers haurdness | 903 MPa |
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Brinell haurdness | 650 MPa |
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CAS Nummer | 7440-67-7 |
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History |
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Diskivery | Martin Heinrich Klaproth (1789) |
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First isolation | Jöns Jakob Berzelius (1824) |
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Main isotopes o zirconium |
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Isotope |
Abundance |
Hauf-life (t1/2) |
Decay mode |
Product |
88Zr |
syn |
83.4 d |
ε |
88Y |
γ |
- |
89Zr |
syn |
78.4 h |
ε |
89Y |
β+ |
89Y |
γ |
- |
90Zr |
51.45% |
stable |
91Zr |
11.22% |
stable |
92Zr |
17.15% |
stable |
93Zr |
trace |
1.53×106 y |
β− |
93Nb |
94Zr |
17.38% |
>1.1×1017 y |
(β−β−) |
94Mo |
96Zr |
2.8% |
2.0×1019 y[4] |
β−β− |
96Mo |
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Decay modes in parentheses are predictit, but hae nae yet been observed |
| references |