The document summarizes the different states of sulfur - solid, liquid, and plastic solid - and the chemical bonds involved in the phase changes. 1) Solid sulfur consists of S8 molecules held together by weak van der Waals forces, which break at 112°C to form a liquid. 2) Heating the liquid to 200°C breaks the stronger covalent bonds, forming long polymer chains that further react to form a viscous substance. 3) Breaking the polymer chains into shorter segments by heating to 444°C produces a runny liquid. 4) Cooling this liquid by adding it to water forms a plastic solid as the shorter chains slow down.