Explain what happens to a crystal of iodine when it is heated (5marks)

A crystal of iodine sublimes from its solid state to its gaseous state without turning into a liquid. Iodine forms a molecular covalent crystal. This means that there are strong covalent bonds within the molecules of I₂ but weak Van der Waals forces holding the molecules of I_{2 i}n the crystalline structure. When Iodine is heated, these weak Van der Waals forces are broken, freeing the gaseous molecules of I₂ from the crystalline structure.