Element 84 · Post-transition metal
Polonium (Po) — Element 84
Poland
Polonium (Po) is a post-transition metal in Period 6, Group 16 of the periodic table with atomic number 84, standard atomic weight [209] u, and ground-state electron configuration [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴. At standard temperature and pressure it is classified as a solid with 6 valence electrons and common oxidation states +2, +4.
Antistatic devices, research
What are the atomic properties and physical constants of Polonium?
Reference constants compiled from IUPAC standard atomic weights, the NIST Atomic Spectra Database, and the CRC Handbook.
- Atomic number (Z)
- 84
- Standard atomic mass
- [209] u
- Chemical family
- Post-transition metal
- Ground-state configuration
- [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴
- Electrons per shell
- 2, 8, 18, 32, 18, 6
- Valence electrons
- 6
- Common ion charges / oxidation states
- +2, +4
- Phase at STP
- Solid
- Pauling electronegativity
- 2.00 Pauling
- First ionization energy
- 812 kJ/mol
- Atomic radius
- 135 pm
- Melting point
- 254 °C
- Boiling point
- 962 °C
- Discovery year
- 1898
- Table coordinate
- Period 6, Group 16
- Radioactivity
- Radioactive (no stable isotopes)
How are electrons arranged across Polonium’s shells?
A neutral Polonium atom contains 84 electrons distributed across 6 occupied principal energy shells ([Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴). The table below compares Polonium’s shell occupancy against each shell’s theoretical 2n² capacity.
| Principal Shell (n) | Spectroscopic Letter | Electrons in Po | Max Shell Capacity (2n²) |
|---|---|---|---|
| n = 1 | K | 2 e⁻ | 2 e⁻ |
| n = 2 | L | 8 e⁻ | 8 e⁻ |
| n = 3 | M | 18 e⁻ | 18 e⁻ |
| n = 4 | N | 32 e⁻ | 32 e⁻ |
| n = 5 | O | 18 e⁻ | 50 e⁻ |
| n = 6 | P | 6 e⁻ | 72 e⁻ |
Frequently Asked Questions about Polonium (Po)
What is the atomic mass and atomic number of Polonium (Po)?
Polonium (Po) has atomic number Z = 84 (84 protons in its nucleus) and an IUPAC standard atomic weight of [209] u. It sits in Period 6, Group 16 and is classified as a post-transition metal.
What is the ground-state electron configuration of Polonium?
The neutral ground-state electron configuration of Polonium (Z = 84) is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴. Across its 6 occupied principal shells (n = 1 to n = 6), the electrons per shell are 2, 8, 18, 32, 18, 6, with 6 valence electrons participating in bonding.
What are the common ion charges and electronegativity of Polonium?
Polonium commonly forms +2, +4 oxidation states or ion charges in compounds. Its Pauling electronegativity is 2.00 and its first ionization energy is 812 kJ/mol.
When was Polonium discovered and what is it used for?
Polonium was discovered in 1898 (Poland). Antistatic devices, research
How does Polonium compare to neighboring elements?
Other post-transition metal elements: