Polonium: the essentials
Polonium has more isotopes than any other element, all of which are radioactive. Polonium dissolves readily in dilute acids, but is only slightly soluble in alkalis.
Weight for weight it is about 2.5 x 1011 times as toxic as hydrocyanic acid (HCN). Polonium has been found in tobacco as a contaminant and in uranium ores.
- Name: polonium
- Symbol: Po
- Atomic number: 84
- Relative atomic mass (Ar): [ 209 ]
- Standard state: solid at 298 K
- Colour: silvery
- Classification: Metallic
- Group in periodic table: 16
- Group name: Chalcogen
- Period in periodic table: 6
- Block in periodic table: p-block
- Electron shell structure: 2.8.18.32.18.6
- CAS Registry ID: 7440-08-6
Image adapted with permission from Prof James Marshall's (U. North Texas, USA) Walking Tour of the elements CD.
Polonium: historical information
Polonium was the first element discovered by Marie Sklodowska Curie in 1898, while seeking the cause of radioactivity of pitchblende from Joachimsthal, Bohemia. It required several tonnes of pitchblende to produce very small amounts of polonium.
Polonium around us Read more »
Polonium has no biological role.
Polonium is produced through decay of the small quantities of the bismuth isotope 210Bi present in pitchblende (uranite, largely UO2). However the quantities are very small. Uranium ores might contain about 0.0001 g of polonium in a tonne of ore. It is more usual to obtain polonium through the neutron bombardment of 209Bi.
| Location | ppb by weight | ppb by atoms | Links |
|---|---|---|---|
| Universe | (no data) | (no data) | 
|
| Crustal rocks | (no data) | (no data) | 
|
| Human | (no data) ppb by weight | (no data) atoms relative to C = 1000000 | 
|
Physical properties Read more »
Density of solid: 9196 kg m-3
Molar volume: |196| cm3
Thermal conductivity: |206| W m‑1 K‑1
Heat properties Read more »
Melting point: 527 [254 °C (489 °F)] K
Boiling point: 1235 [962 °C (1764 °F)] K
Enthalpy of fusion: |203| kJ mol-1
Crystal structure Read more »
The solid state structure of polonium is: cubic.
Polonium: orbital properties Read more »
Polonium atoms have 84 electrons and the shell structure is 2.8.18.32.18.6. The ground state electronic configuration of neutral Polonium is [Xe].4f14.5d10.6s2.6p4 and the term symbol of Polonium is 3P2.
Pauling electronegativity: 2.0 (Pauling units)
First ionisation energy: 812.1 kJ mol‑1
Second ionisation energy: (no data) kJ mol‑1
Isolation
Isolation: polonium is radioactive and excessivley rare in nature. It is made in very small qunatities through a nuclear reaction of bismuth. Neutron irradiation of 209bismuth (atomic number 83) gives 210polonium (atomic number 84).
209Bi + 1n → 210Po + e-
Metallic polonium can be fractionally distilled from the bismuth or electrodeposited onto a metal surface such as silver.
Polonium isotopes Read more »
| Isotope | Mass /Da |
Natural abund. (atom %) |
Nuclear spin (I) |
Nuclear magnetic moment (μ/μN) |
|---|---|---|---|---|
| nil |
WebElements chemistry shop
You can buy periodic table posters, mugs, T-shirts, periodic table fridge magnets, games, molecular models, and more at the WebElements periodic table shop
