Polonium
post-transition metal · period 6 · group 16 (chalcogens) · p-block
Polonium is a chemical element with the symbol Po and atomic number 84. Polonium is a chalcogen.
What the numbers say
At standard temperature and pressure Polonium is a solid, sitting in period 6, group 16 of the p-block.
Its melting point of 527 K (254 °C) is the 82nd highest of the 110 elements with a measured value — mid-range among the elements.
At 9.196 g/cm³ it is the 31st densest of 96 elements with a quoted density.
Pauling electronegativity is 2. Paired with oxygen (3.44) that is a difference of 1.44, 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 cubic structure.
It is reported in 4 oxidation states (-2, 2, 4, 6), which sets how many distinct compounds and phases it can form.
First identified in 1898.
Crystal structure
Solid Polonium adopts a Simple Cubic arrangement, in the Cubic (isometric) system — axes a = b = c, 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 Po — with DFT formation energy, hull stability and band gap where the provider publishes them.
K 2 · L 8 · M 18 · N 32 · O 18 · P 6
Properties
| Atomic number | 84 |
|---|---|
| Atomic mass | 209 u |
| Series | post-transition metal |
| Group | 16 |
| Period | 6 |
| Block | p-block |
| Phase at STP | Solid |
| Density | 9.196 g/cm³ |
| Melting point | 527 K (254 °C) |
| Boiling point | 1235 K (962 °C) |
| Electronegativity (Pauling) | 2 |
| Electron configuration | [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴ |
| Crystal structure | Simple Cubic |
| Oxidation states | -2,2,4,6 |
| Discovered | 1898 |
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See Po in context with all 118 elements.
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