Polonium (Po)

Silvery

Polonium is a rare, highly radioactive element discovered by Marie Curie in 1898, and with two unpaired 6p electrons, polonium-210 (half-life 138 days) emits alpha particles so intensely it glows blue and generates 140 watts per gram. It was used in the assassination of Alexander Litvinenko in 2006.

Key metrics

Density9.2g/cm³

Melting point527K

Boiling point1,235K

Electronegativity2Pauling

Discovery

1898discovered

Discovered by: Marie Curie
Reactivity profile: Highly radioactive
Reactivity: High
Bonding: Covalent

Electron configuration

\textcolor{#6b7280}{[Xe]}\; \textcolor{#a855f7}{4_{f}^{14}}\; \textcolor{#22c55e}{5_{d}^{10}}\; \textcolor{#ef4444}{6_{s}^{2}}\; \textcolor{#3b82f6}{6_{p}^{4}}

[Xe] 4f14 5d10 6s2 6p4

Wave function

\Psi_{\text{Po}} \approx \frac{1}{\sqrt{84!}} \det \left| \chi_1(\mathbf{r}_1) \dots \chi_{84}(\mathbf{r}_{84}) \right|

Probability density $|\Psi|^2$ across the Po valence shell.

Crystal structure

Simple Cubic

Lattice constantsa = 1.00

Cell anglesα = β = γ = 90°

Coordination number6

Atoms per cell1

Atomic packing factor0.52

Physical properties

Atomic radius: 135 pm
Ionization energy: 812 kJ/mol
Electron affinity: 183 kJ/mol
Crystal structure: Simple cubic

Oxidation states

-2+2+4+6

Acid/base

Can act as acid or base

Strongly acidicStrongly basic

State at 25 °CSolid

527 K1235 K298 K

Emission spectrum

3 transitions

380450500550600650700780

VioletBlueGreenYellowRed

485.3nmPo I (blue)Blue60%

538.1nmPo I (green)Green40%

568.1nmPo I (yellow)Yellow100%

Dominant line 568.1 nmRange 485–568 nmTransitions 3