Polonium tetranitrate

Polonium tetranitrate is an inorganic compound, a salt of polonium and nitric acid with the chemical formula Po(NO3)4. The compound is radioactive, forms white crystals.

Synthesis
Dissolution of metallic polonium in concentrated nitric acid:
 * $$\mathsf{ Po + 8 HNO_3 \ \xrightarrow{}\ Po(NO_3)_4 + 4 NO_2\uparrow + 4 H_2O }$$

Physical properties
Polonium(IV) nitrate forms white or colorless crystals. It dissolves in water with hydrolysis.

Chemical properties
It disproportionates in aqueous weakly acidic nitric acid solutions:
 * $$\mathsf{ 2 Po(NO_3)_4 + 2H_2O \ \xrightarrow{}\ PoO_2(NO_3)_2\downarrow + Po^ + 2NO_3^- + 4HNO_3 }$$

The polonium(II) ion (Po2+) is then oxidized by nitric acid to polonium(IV).