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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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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 |
100 |
1 k |
10 k |
100 k |
at T (K) |
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|
(775) |
(888) |
1042 |
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 | 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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Isotope |
Abundance |
Hauf-life (t1/2) |
Decay mode |
Product |
120Te |
0.09% |
>2.2×1016 y |
(β+β+) |
120Sn |
121Te |
syn |
16.78 d |
ε |
121Sb |
122Te |
2.55% |
- |
(SF) |
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123Te |
0.89% |
>5×1019 y |
(ε) |
123Sb |
124Te |
4.74% |
- |
(SF) |
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125Te |
7.07% |
- |
(SF) |
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126Te |
18.84% |
- |
(SF) |
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127Te |
syn |
9.35 h |
β− |
127I |
128Te |
31.74% |
2.2×1024 y |
β−β− |
128Xe |
129Te |
syn |
69.6 min |
β− |
129I |
130Te |
34.08% |
7.9×1020 y |
β−β− |
130Xe |
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Decay modes in parentheses are predictit, but hae nae yet been observed |
| references |