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Tellurium |
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Pronunciation | (tih-LEWR-ee-əm) |
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Appearance | sillery lustrous gray |
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Standard atomic weight Ar, std(Te) | 7002127600000000000♠127.60(3)[1] |
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Mass number | Te: |
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Tellurium in the periodic cairt |
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Atomic nummer (Z) | 52 |
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Group | group 16 (chalcogens) |
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Period | period 5 |
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Block | p-block |
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Element category | Metalloid |
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Electron confeeguration | [Kr] 4d10 5s2 5p4 |
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Electrons per shell | 2, 8, 18, 18, 6 |
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Pheesical properties |
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Phase at STP | solit |
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Meltin pynt | 722.66 K (449.51 °C, 841.12 °F) |
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Bylin pynt | 1261 K (988 °C, 1810 °F) |
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Density (near r.t.) | 6.24 g/cm3 |
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when liquid (at m.p.) | 5.70 g/cm3 |
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Heat o fusion | 17.49 kJ/mol |
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Heat o vapourisation | 114.1 kJ/mol |
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Molar heat capacity | 25.73 J/(mol·K) |
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Vapour pressur
P (Pa)
|
1
|
10
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100
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1 k
|
10 k
|
100 k
|
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at T (K)
|
|
|
(775)
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(888)
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1042
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1266
|
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Atomic properties |
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Oxidation states | −2, −1, +1, +2, +3, +4, +5, +6 (a mildly acidic oxide) |
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Electronegativity | Pauling scale: 2.1 |
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Atomic radius | empirical: 140 pm |
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Covalent radius | 138±4 pm |
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Van der Waals radius | 206 pm |
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Spectral lines o tellurium |
Ither properties |
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Naitural occurrence | Te: Primordial |
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Creestal structur | hexagonal[2] |
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Speed o soond thin rod | 2610 m/s (at 20 °C) |
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Thermal conductivity | (1.97–3.38) W/(m·K) |
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Magnetic orderin | diamagnetic[3] |
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Young's modulus | 43 GPa |
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Shear modulus | 16 GPa |
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Bulk modulus | 65 GPa |
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Mohs haurdness | 2.25 |
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Brinell haurdness | 180 MPa |
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CAS Nummer | 13494-80-9 |
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History |
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Diskivery | Franz-Joseph Müller von Reichenstein (1782) |
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First isolation | Martin Heinrich Klaproth |
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Main isotopes o tellurium |
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Decay modes in parentheses are predictit, but hae nae yet been observed |
| references |