At what temperatures does sulfur melt and boil?

The melting and boiling points of sulfur depend on its allotropic form and heating conditions.

Melting Point

Because sulfur exhibits allotropy, its melting point varies based on the crystalline structure:
* $\alpha$-sulfur (orthorhombic): If heated rapidly, it melts at 112.8 °C (235 °F). If allowed to transform into the $\beta$-form, it melts at 118.9 °C (246 °F).12
* $\beta$-sulfur (monoclinic): This form melts at 118.9 °C (246 °F).12

Boiling Point

The boiling point of sulfur is 444.6 °C (832.3 °F).12

As the liquid is heated toward this temperature, its physical properties—such as viscosity and color—undergo significant changes due to the breaking and reforming of sulfur molecular chains. Upon vaporization, the element forms cyclic molecules, eventually breaking down into smaller fragments like $S_2$ and monatomic sulfur at much higher temperatures.1