Tellurium
metalloid · period 5 · group 16 (chalcogens) · p-block
Tellurium is a chemical element with the symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid.
What the numbers say
At standard temperature and pressure Tellurium is a solid, sitting in period 5, group 16 of the p-block.
Its melting point of 723 K (450 °C) is the 72nd highest of the 110 elements with a measured value — mid-range among the elements.
At 6.24 g/cm³ it is the 56th densest of 96 elements with a quoted density.
Pauling electronegativity is 2.1. Paired with oxygen (3.44) that is a difference of 1.34, which puts the bond polar covalent — oxides here tend to be semiconducting or refractory rather than salt-like.
In the solid state it takes a simple trigonal structure.
It is reported in 5 oxidation states (-2, 2, 4, 5, 6), which sets how many distinct compounds and phases it can form.
First identified in 1783.
Crystal structure
Solid Tellurium adopts a Simple Trigonal arrangement, in the Trigonal (rhombohedral) system — axes a = b = c (rhombohedral setting), angles α = β = γ ≠ 90°. Symmetry controls the anisotropy of stiffness and thermal expansion, and the available slip systems set how far the metal deforms before it fractures.
Check it against computed structures
The structure search queries the Materials Project, OQMD and the Open Materials Database for computed crystal structures containing Te — with DFT formation energy, hull stability and band gap where the provider publishes them.
K 2 · L 8 · M 18 · N 18 · O 6
Properties
| Atomic number | 52 |
|---|---|
| Atomic mass | 127.603 u |
| Series | metalloid |
| Group | 16 |
| Period | 5 |
| Block | p-block |
| Phase at STP | Solid |
| Density | 6.24 g/cm³ |
| Melting point | 722.66 K (450 °C) |
| Boiling point | 1261 K (988 °C) |
| Electronegativity (Pauling) | 2.1 |
| Electron configuration | [Kr] 4d¹⁰ 5s² 5p⁴ |
| Crystal structure | Simple Trigonal |
| Oxidation states | -2,2,4,5,6 |
| Discovered | 1783 |
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See Te in context with all 118 elements.
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