is heating iodine from its solid state to a liquid state a chemical or physical change?

It is still iodine; therefore, physical change.

physical change. It is still iodine I2. Curiously, iodine cannot be found as an atomic element in nature, but only as a diatomic molecule I2, made up of two iodine atoms.

Heating iodine from its solid state to a liquid state is a physical change. In a physical change, the substance undergoes a change in its state or appearance but its chemical composition remains the same. In this case, the iodine molecules rearrange their positions and gain enough energy to overcome the attractive forces holding them in a solid lattice, resulting in the formation of a liquid.

To determine whether a change is chemical or physical, we can apply a general rule: if the chemical composition of the substance remains unchanged, it is a physical change. In the case of heating iodine, the individual iodine atoms or molecules are not altered chemically—they remain as iodine. Therefore, the change is classified as a physical change.