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 I2 in 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.
