Query: what are the only two oxidation states known for zinc?
Context: The volatilization of zinc in combination with zinc chloride at temperatures above 285 °C indicates the formation of Zn
2Cl
2, a zinc compound with a +1 oxidation state. No compounds of zinc in oxidation states other than +1 or +2 are known. Calculations indicate that a zinc compound with the oxidation state of +4 is unlikely to exist.