Allotropy exhibited by α and β forms of sulphur is called

α and β forms of sulphur coexist at 369KThere exists a dynamic equilibrium between them.This is called enantiotropy (or) Dynamic allotropyBelow 369K , α-sulphur(rhombic) is stableIt is thermodynamically most stable form of sulphurAbove 369K , β- sulphur is stable