Question

Open container on heating solid sulphur melts but solid iodine sublime explain

Answer 1

Explanation:

This is because iodine on being a sublimable* substance will on heating turn into its gaseous state whereas  solid sulphur will melt and on further heating can indeed be converted to its gaseous state but not directly.

* a sublimable solid is one that on heating turns directly into its gaseous stat and does not get converted to its liquid state.