Element 84
Polonium (Po)
Polonium (Po) is element 84 of the periodic table, a metalloid in period 6, group 16 (p-block) with an atomic mass of 209 and is a solid at standard conditions.
At a glance
- Atomic number
- 84
- Symbol
- Po
- Atomic mass
- 209 u
- Category
- Metalloids
- Period
- 6
- Group
- 16
- Block
- p-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p4
- Shorthand configuration
- [Xe] 4f14 5d10 6s2 6p4
- Electrons per shell
- 2, 8, 18, 32, 18, 6
- Oxidation states
- -2, +2, +4, +5, +6
Physical properties
- Melting point
- 527 K (253.85 °C)
- Boiling point
- 1,235 K (961.85 °C)
- Density
- 9.32 g/cm³
- Phase
- solid
Atomic properties
- Electronegativity (Pauling)
- 2
- Atomic radius
- 135 pm
- Covalent radius
- 140 pm
- Van der Waals radius
- 197 pm
- First ionization energy
- 812 kJ/mol
- Electron affinity
- 136 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Po-209 | 208.98243 | - | Half-life 125 years |
Common uses
- Heat source for satellites
- Anti-static devices
- Nuclear weapons
Discovery
- Year
- 1898
- Discovered by
- Marie Curie, Pierre Curie
- Country
- France
Frequently asked questions
- Is polonium a metal?
- Polonium is a metalloid, which means it shows properties of both metals and nonmetals.
- How many protons does polonium have?
- Polonium has 84 protons. Its atomic number is 84, which is also the number of electrons in a neutral atom of polonium.
- What group and period is polonium in?
- Polonium is in group 16 and period 6 of the periodic table, in the p-block.
- What is the atomic mass of polonium?
- The atomic mass of polonium is 209 u (unified atomic mass units).
Keep exploring
Polonium's row is on the printable element property sheet, and its tile is on the periodic table wall chart - the same numbers as above, laid out for A4 or A3 paper.