Melting ice is considered a physical change because it involves a change in the state of matter without altering the chemical composition of the substance. When ice melts, it turns from a solid state into a liquid state, but the water molecules remain the same. The process is reversible, meaning that if you freeze the water again, it will turn back into ice.
In a physical change, the substance’s molecular structure does not change. The water molecules in ice are arranged in a crystalline structure, and when the ice melts, these molecules gain enough energy to break free from the crystalline arrangement and move more freely, forming liquid water. However, the chemical identity of the water molecules (H2O) remains unchanged.
This is different from a chemical change, where the substance’s molecular structure is altered, resulting in the formation of new substances with different properties. Since melting ice only involves a change in the physical state and not the chemical composition, it is classified as a physical change.