Polonium (Po)
Post-transition metal · p-block · period 6 · group 16
Silvery-grey, intensely radioactive metal that glows and warms itself.
Polonium (symbol Po) is chemical element number 84, a post-transition metal in group 16, period 6 of the periodic table. Its standard atomic weight is (209) and its electron configuration is [Xe] 4f14 5d10 6s2 6p4. At room temperature it is a solid, and it is radioactive. The first element discovered by Marie Curie, who named it after her homeland Poland.
Properties
| Atomic number | 84 |
|---|---|
| Atomic mass | (209) |
| Category | Post-transition metal |
| Block | p-block |
| Group · Period | 16 · 6 |
| Electron configuration | [Xe] 4f14 5d10 6s2 6p4 |
| Electrons per shell | 2, 8, 18, 32, 18, 6 |
| State at 25 °C | solid |
| Melting point | 527 K |
| Boiling point | 1235 K |
| Density | 9.2 g/cm³ |
| Electronegativity (Pauling) | 2 |
| Radioactive | Yes — no stable isotope |
| Origin | decay |
| Discovered | 1898 · Marie & Pierre Curie |
Key facts about Polonium
- The first element discovered by Marie Curie, who named it after her homeland Poland.
- So radioactive that a gram of it glows blue and stays at several hundred degrees from its own decay.
- About 250 billion times more toxic than hydrogen cyanide by weight.
- Used to murder the dissident Alexander Litvinenko in 2006.
What Polonium is used for
Static-eliminator brushes, lightweight heat sources for old spacecraft and lunar rovers, neutron sources.
Where it sits in the periodic table
Polonium is in group 16, period 6, of the p-block. Its electron configuration [Xe] 4f14 5d10 6s2 6p4 means its outermost shell holds 6 electrons, which is what places it here and explains much of its chemistry. See Polonium on the interactive table →
Polonium — frequently asked questions
What is Polonium used for?
Static-eliminator brushes, lightweight heat sources for old spacecraft and lunar rovers, neutron sources.
Is Polonium radioactive?
Yes. Polonium has no stable isotope, so every form of it is radioactive.
What is the electron configuration of Polonium?
Polonium has the electron configuration [Xe] 4f14 5d10 6s2 6p4, which is 2, 8, 18, 32, 18, 6 electrons per shell.
What group and period is Polonium in?
Polonium is in group 16, period 6, in the p-block. Its outer shell holds 6 electrons.
Who discovered Polonium?
Polonium was discovered in 1898 by Marie & Pierre Curie.