Template:Infobox tellurium

Tellurium,  ₅₂Te

General properties
Name, symbol	tellurium, Te
Appearance	silvery lustrous gray (crystalline), brown-black powder (amorphous)
Pronunciation	/tᵻˈlʲʊəriəm/ te-LEWR-ee-əm
Tellurium in the periodic table
Se ↑ Te ↓ Po antimony ← tellurium → iodine
Atomic number (Z)	52
Group, block	group 16 (chalcogens), p-block
Period	period 5
Element category	metalloid
Standard atomic weight (±) (Ar)	127.60(3)
Electron configuration	[Kr] 4d10 5s2 5p4
per shell	2, 8, 18, 18, 6
Physical properties
Phase	solid
Melting point	722.66 K ​(449.51 °C, ​841.12 °F)
Boiling point	1261 K ​(988 °C, ​1810 °F)
Density near r.t.	6.24 g/cm3
when liquid, at m.p.	5.70 g/cm3
Heat of fusion	17.49 kJ/mol
Heat of vaporization	114.1 kJ/mol
Molar heat capacity	25.73 J/(mol·K)
vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K)   (775) (888) 1042 1266
Atomic properties
Oxidation states	6, 5, 4, 3, 2, 1, −1, −2 ​(a mildly acidic oxide)
Electronegativity	Pauling scale: 2.1
Ionization energies	1st: 869.3 kJ/mol 2nd: 1790 kJ/mol 3rd: 2698 kJ/mol
Atomic radius	empirical: 140 pm
Covalent radius	138±4 pm
Van der Waals radius	206 pm
Miscellanea
Crystal structure	​hexagonal
Speed of sound thin rod	2610 m/s (at 20 °C)
Thermal expansion	18 µm/(m·K) (at r.t.)
Thermal conductivity	1.97–3.38 W/(m·K)
Magnetic ordering	diamagnetic
Young's modulus	43 GPa
Shear modulus	16 GPa
Bulk modulus	65 GPa
Mohs hardness	2.25
Brinell hardness	180–270 MPa
CAS Number	13494-80-9
History
Naming	after Roman Tellus, deity of the Earth
Discovery	Franz-Joseph Müller von Reichenstein (1782)
First isolation	Martin Heinrich Klaproth
Most stable isotopes of tellurium
iso NA half-life DM DE (MeV) DP 120Te 0.09% >2.2×1016 y (β+β+) 1.701 120Sn 121Te syn 16.78 d ε 1.040 121Sb 122Te 2.55% – (SF) <30.974 123Te 0.89% >9.2×1016 y (ε) 0.051 123Sb 124Te 4.74% – (SF) <28.221 125Te 7.07% – (SF) <26.966 126Te 18.84% – (SF) <26.011 127Te syn 9.35 h β− 0.698 127I 128Te 31.74% 2.2×1024 y β−β− 0.867 128Xe 129Te syn 69.6 min β− 1.498 129I 130Te 34.08% 7.9×1020 y β−β− 2.528 130Xe
Decay modes in parentheses are predicted, but have not yet been observed

References

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