84209PoPolonium
Polonium (Po) — element 84post-transition metal · group 16, period 6
Polonium is a chemical element with the symbol Po and atomic number 84. It is a post-transition metal in group 16, period 6 of the periodic table (the p-block), with a standard atomic mass of 209 u. At room temperature (25 °C) polonium is a solid.
💡 Known for: Highly radioactive; discovered by Marie and Pierre Curie and named after Poland.
# Polonium properties
| Symbol | Po |
|---|---|
| Atomic number | 84 |
| Atomic mass | 209 u |
| Category | post-transition metal |
| Group | 16 |
| Period | 6 |
| Block | p-block |
| Electron configuration | [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴ |
| Full configuration | 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁴ |
| Electrons per shell | 2, 8, 18, 32, 18, 6 |
| Protons / electrons | 84 / 84 |
| State at 25 °C | solid |
| Melting point | 527 K (253.9 °C, 488.9 °F) |
| Boiling point | 1235 K (961.9 °C, 1763.3 °F) |
| Density | 9.32 g/cm³ |
| Electronegativity (Pauling) | 2 |
| First ionization energy | 8.414 eV |
| Atomic radius | 135 pm |
| Discovered | 1898 |
# Electron configuration of polonium
The electron configuration of polonium is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴, written out in full as 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁴. Its 84 electrons fill 6 shells as 2, 8, 18, 32, 18, 6, so the outermost shell holds 6 electrons. As a group 16 element, polonium has 6 valence electrons.
# Related elements
BiBismuthprevious elementAtAstatinenext elementOOxygengroup 16SSulfurgroup 16SeSeleniumgroup 16TeTelluriumgroup 16LvLivermoriumgroup 16AlAluminiumpost-transition metalGaGalliumpost-transition metalInIndiumpost-transition metalSnTinpost-transition metalTlThalliumpost-transition metalPbLeadpost-transition metalNhNihoniumpost-transition metalFlFleroviumpost-transition metal
# Polonium FAQ
What is the atomic number of polonium?
The atomic number of polonium is 84: every polonium atom has 84 protons in its nucleus. Its symbol is Po.
What is the atomic mass of polonium?
The standard atomic mass of polonium is 209 u.
What is the electron configuration of polonium?
Polonium's electron configuration is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴ (1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁴), with 2, 8, 18, 32, 18, 6 electrons per shell.
Is polonium a metal?
Yes. Polonium is a post-transition metal, one of the metals.
What is the melting point of polonium?
Polonium melts at 527 K (253.9 °C, 488.9 °F) and boils at 1235 K (961.9 °C, 1763.3 °F).
What is polonium used for / known for?
Highly radioactive; discovered by Marie and Pierre Curie and named after Poland.