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Pronunciation | (te-LURE-ee-əm) |
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Appearance | silvery lustrous gray (crystalline), brown-black powder (amorphous) |
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| 127.60(3)[1] |
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Atomic number (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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Electron configuration | [Kr] 4d10 5s2 5p4 |
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Electrons per shell | 2, 8, 18, 18, 6 |
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Phase at STP | solid |
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Melting point | 722.66 K (449.51 °C, 841.12 °F) |
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Boiling point | 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 of fusion | 17.49 kJ/mol |
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Heat of vaporization | 114.1 kJ/mol |
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Molar heat capacity | 25.73 J/(mol·K) |
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Vapor pressure
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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Oxidation states | −2, −1, 0, +1, +2, +3, +4, +5, +6 (a mildly acidic oxide) |
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Electronegativity | Pauling scale: 2.1 |
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Ionization energies | - 1st: 869.3 kJ/mol
- 2nd: 1790 kJ/mol
- 3rd: 2698 kJ/mol
-
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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 of tellurium |
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Natural occurrence | primordial |
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Crystal structure | trigonal[2] |
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Speed of sound thin rod | 2610 m/s (at 20 °C) |
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Thermal expansion | 18 µm/(m⋅K)[3] (at r.t.) |
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Thermal conductivity | 1.97–3.38 W/(m⋅K) |
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Magnetic ordering | diamagnetic[4] |
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Molar magnetic susceptibility | −39.5×10−6 cm3/mol (298 K)[5] |
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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 hardness | 2.25 |
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Brinell hardness | 180–270 MPa |
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CAS Number | 13494-80-9 |
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Naming | after Roman Tellus, deity of the Earth |
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Discovery | Franz-Joseph Müller von Reichenstein (1782) |
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First isolation | Martin Heinrich Klaproth |
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Main isotopes[6] |
Decay |
|
abundance |
half-life (t1/2) |
mode |
product |
120Te |
0.09% |
stable |
121Te |
synth |
16.78 d |
ε |
121Sb |
122Te |
2.55% |
stable |
123Te |
0.89% |
stable[7] |
124Te |
4.74% |
stable |
125Te |
7.07% |
stable |
126Te |
18.8% |
stable |
127Te |
synth |
9.35 h |
β− |
127I |
128Te |
31.7% |
2.2×1024 y |
β−β− |
128Xe |
129Te |
synth |
69.6 min |
β− |
129I |
130Te |
34.1% |
8.2×1020 y |
β−β− |
130Xe |
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Category: Tellurium | references |