Po
Polonium
Element 84 · Metalloid
Polonium (Po)
Polonium is a rare, highly radioactive metal. Gram for gram, it is one of the most toxic substances known.
- Metalloid
- Period 6
- Group 16
- p-block
- solid at room temperature
- ☢ Radioactive
Key properties
- Atomic mass
- [209]
- u
- Electron configuration
- [Xe] 4f14 5d10 6s2 6p4
- Melting point
- 253.9 °C
- 527 K
- Boiling point
- 961.9 °C
- 1,235 K
- Density
- 9.32 g/cm³
- Electronegativity
- 2
- Pauling
- Atomic radius
- 197 pm
- van der Waals
- 1st ionisation energy
- 8.417 eV
Compare with every element:Electronegativity chartAtomic radius chartIonisation energy chartDensity chart of the elementsMelting point chartElectron configuration chart
Did you know?
Notable facts about polonium
- 01
It was the first element discovered by the Curies, months before radium.
- 02
Polonium-210 was used to poison former Russian officer Alexander Litvinenko in 2006.
- 03
Polonium releases so much energy that a gram heats itself to around 500 °C.
Applications
What is polonium used for?
- Anti-static brushes
- Neutron sources
- Heat sources in space probes (historically)
History
Discovery & name origin
Discovered by
Year
Where
France
Name origin
From Poland, Marie Curie’s homeland.
Atomic structure
Atomic properties
Atomic structure
Atomic properties
- Atomic number
- 84
- Atomic mass
- [209] u
- Group
- 16
- Period
- 6
- Block
- p-block
- Electron configuration
- [Xe] 4f14 5d10 6s2 6p4
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p4
- Electrons per shell
- 2, 8, 18, 32, 18, 6
- Electronegativity (Pauling)
- 2
- Electron affinity
- 1.9 eV
- Atomic radius (van der Waals)
- 197 pm
- Stable isotopes
- None — all isotopes are radioactive
Oxidation states
Highlighted: common oxidation states (+4, +2).
Physical
Physical properties & colour
Physical
Physical properties & colour
- State at 20 °C
- Solid
- Melting point
- 527 K · 253.9 °C · 488.9 °F
- Boiling point
- 1,235 K · 961.9 °C · 1,763.3 °F
- Density
- 9.32 g/cm³
- Molar heat capacity
- 26.4 J/(mol·K)
- Appearance
- Silvery
- CPK model colour
- Copied
The CPK colour is the convention used for this element’s atoms in molecular models.
FAQ
Polonium questions
What is Po on the periodic table?
Po is the symbol for polonium, element 84 on the periodic table. It sits in group 16, period 6, in the metalloid category, and has an atomic mass of [209].
What is the atomic number of polonium?
Polonium has atomic number 84, so every polonium atom has 84 protons in its nucleus. Its symbol is Po and its atomic mass is [209].
Who discovered polonium?
Polonium was discovered by Marie Curie and Pierre Curie in 1898 (France). The name comes from from Poland, Marie Curie’s homeland.
What is polonium used for?
Polonium is used for: anti-static brushes; neutron sources; heat sources in space probes (historically).
Is polonium a metal?
No. Polonium is classed as a metalloid, with properties between metals and nonmetals.
What is the electron configuration of polonium?
The electron configuration of polonium is [Xe] 4f14 5d10 6s2 6p4. Its 84 electrons are arranged in shells as 2, 8, 18, 32, 18, 6.