Why is sulphur a good insulator of electricity?

Sulphur is a good electrical insulator primarily due to its molecular structure. It has a high electron affinity and does not have free electrons that can move easily, which is essential for electrical conductivity. Additionally, sulphur's covalent bonding in solid form creates a stable lattice structure that inhibits the flow of electric current. Consequently, these properties make sulphur effective at preventing the passage of electricity.