Polonium dioxide

Polonium dioxide (also known as polonium(IV) oxide) is a chemical compound with the formula PoO₂. It is one of three oxides of polonium, the other two being polonium monoxide (PoO) and polonium trioxide (PoO₃). It is a pale yellow crystalline solid at room temperature. Under lowered pressure (such as a vacuum), it decomposes into elemental polonium and oxygen at 500 °C. It is the most stable oxide of polonium and is an interchalcogen.