Antimony
metalloid · period 5 · group 15 (pnictogens) · p-block
Antimony is a chemical element with the symbol Sb (from Latin: stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3).
What the numbers say
At standard temperature and pressure Antimony is a solid, sitting in period 5, group 15 of the p-block.
Its melting point of 904 K (631 °C) is the 70th highest of the 110 elements with a measured value — mid-range among the elements.
At 6.697 g/cm³ it is the 51st densest of 96 elements with a quoted density.
Pauling electronegativity is 2.05. Paired with oxygen (3.44) that is a difference of 1.39, 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 3 oxidation states (-3, 3, 5), which sets how many distinct compounds and phases it can form.
First identified in c. 3000 BCE.
Crystal structure
Solid Antimony 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 Sb — with DFT formation energy, hull stability and band gap where the provider publishes them.
K 2 · L 8 · M 18 · N 18 · O 5
Properties
| Atomic number | 51 |
|---|---|
| Atomic mass | 121.7601 u |
| Series | metalloid |
| Group | 15 |
| Period | 5 |
| Block | p-block |
| Phase at STP | Solid |
| Density | 6.697 g/cm³ |
| Melting point | 903.78 K (631 °C) |
| Boiling point | 1908 K (1635 °C) |
| Electronegativity (Pauling) | 2.05 |
| Electron configuration | [Kr] 4d¹⁰ 5s² 5p³ |
| Crystal structure | Simple Trigonal |
| Oxidation states | -3,3,5 |
| Discovered | c. 3000 BCE |
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See Sb in context with all 118 elements.
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