Predict the formula of polonium(IV) oxide.
Po4+ with O2- crosses to PoO2 — mirroring TeO2 above it. Radiochemists confirmed it with samples measured in micrograms.
What Is the Charge of Polonium?
Polonium commonly forms Po2+ Po4+ in introductory ionic compounds.
Polonium — the element Marie Curie named for her homeland — shows +2 and +4 states (PoCl2, PoO2), leaning metallic despite sitting in oxygen's group. Its chemistry is studied in trace amounts only: every isotope is intensely radioactive.
| Element | Polonium |
|---|---|
| Symbol | Po |
| Atomic number | 84 |
| Common ionic charge | +2, +4 |
| Common ions | Po2+, Po4+ |
Visual reference
Polonium element image and atomic model
Images are used as visual references; charge rules still depend on the compound.
How Polonium's outer electrons decide its charge
Polonium is [Xe]4f14 5d10 6s2 6p4. On paper it could be -2 like tellurium above it, and polonides (Na2Po) do exist — but by period 6 the group has turned metallic, so cationic +2 and +4 states dominate what little bench chemistry its radioactivity permits.
The Polonium mistake worth a warning
Treating polonium's danger as a charge/chemistry problem. Po-210's alpha decay makes it roughly a million times more toxic than cyanide by mass — but only if ingested; the alphas cannot cross paper or skin. The hazard ledger is nuclear, the (modest) chemistry is a footnote.
Worked example: Po in a formula problem
Po2+ and Po4+ in real compounds
PoCl2
Polonium chloride
Po2+ balances chloride ions.
PoO
Polonium oxide
Polonium can form oxides where total positive and negative charge balances.
Questions students ask about polonium
Why did antistatic brushes contain polonium?
Po-210's alpha particles ionize air, letting static charge bleed off film and vinyl. The polonium sat plated as metal (charge 0), its nucleus doing the work — modern brushes use safer isotopes.
What does polonium's heat mean physically?
A half-gram of Po-210 self-heats past 500 °C from its own alpha decay — energy per gram thousands of times chemical fuels' — which made it an early spacecraft heat source. Nothing to do with its ionic states.
Is polonium the last 'chalcogen'?
It closes oxygen's group and illustrates the family's full arc: gas (O), yellow nonmetal (S), semiconductors (Se, Te), then a radioactive metal (Po) whose 'chalcogen' -2 barely survives as exotic polonides.
How do I use this charge in formulas?
Combine positive and negative ions so the total charge is zero — or let the ionic compound calculator do the crossing for you. The full chart lives on the periodic table with charges.
Where this data comes from
Charges and element facts on this page are checked against the primary references below. Found an error? Email hello@periodictablewithcharges.com — corrections ship in the next content update. See how this site is edited.