Polonium (Po): electron configuration, atomic mass and facts
Polonium (Po) is element 84 of the periodic table, a post-transition metal in period 6, group 16. Its electron configuration is [Xe] 4f14 5d10 6s2 6p4, with electrons arranged in shells 2, 8, 18, 32, 18, 6, and its most stable isotope has mass number 209.
💡 Discovered by Marie and Pierre Curie in 1898 and named after Poland.
▶ Watch Polonium’s electrons orbit in the interactive periodic tablePolonium at a glance
| Symbol | Po |
|---|---|
| Atomic number | 84 |
| Atomic mass | [209] u (most stable isotope) |
| Category | Post-transition metal |
| Group | 16 |
| Period | 6 |
| Block | p-block |
| Electron configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p4 |
| Noble-gas shorthand | [Xe] 4f14 5d10 6s2 6p4 |
| Electrons per shell | 2, 8, 18, 32, 18, 6 |
| Outer-shell electrons | 6 |
| Electronegativity (Pauling) | 2 |
| State at 20 °C | solid |
Where is Polonium on the periodic table?
Polonium is in period 6, group 16, in the p-block. The period number matches its 6 electron shells, and the block names the subshell its last electrons fill. In the same group, Tellurium sits directly above it and Livermorium sits directly below it. Elements in one group have the same number of outer-shell electrons (6 here), which is why they react in similar ways.
How to work out the electron configuration of Polonium
Put 84 electrons into subshells in order of rising energy, filling each before starting the next: 1s² (2), 2s² (4), 2p⁶ (10), 3s² (12), 3p⁶ (18), 4s² (20), 3d¹⁰ (30), 4p⁶ (36), 5s² (38), 4d¹⁰ (48), 5p⁶ (54), 6s² (56), 4f¹⁴ (70), 5d¹⁰ (80), 6p⁴ (84). In shorthand, [Xe] stands for the 54 electrons of xenon, giving [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴.
How electronegative is Polonium?
Polonium has a Pauling electronegativity of 2, ranking 32 of the 100 elements with a known value (fluorine is highest at 3.98). That is in the middle of the range.
Frequently asked questions
What is the electron configuration of Polonium?
The electron configuration of Polonium (Po) is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p4. In noble-gas shorthand it is written [Xe] 4f14 5d10 6s2 6p4.
How many electrons does Polonium have in each shell?
Polonium has 84 electrons arranged in shells as 2, 8, 18, 32, 18, 6. It has 6 electrons in its outer shell.
What is the atomic mass of Polonium?
Polonium has no stable isotopes. Its most stable isotope has a mass number of 209.
Is Polonium a metal?
Yes. Polonium is a post-transition metal.
Explore nearby elements
More post-transition metals: Thallium, Lead, Bismuth, Nihonium, Flerovium, Moscovium. See all elements on the periodic table.