Question

An allotrope of sulphur which is stable at room temperature is _____ sulphur.

Answer 1

Sulphur is a non-metal which exists in different crystal structures known as allotropes.

The stable form of sulphur at room temperature is called rhombic sulphur, and when this is heated slowly above about 95ºC, it transforms into monoclinic sulphur. Both forms are crystals made of S8 molecules.

So, the correct answer is rhombic.