Why is melting ice a physical change?

Melting ice is a physical change because it involves a change in state from solid to liquid without altering its chemical composition.

In more detail, a physical change is a type of change in which the form of matter is altered but one substance is not transformed into another. The original substance still retains its chemical identity. When ice melts, it changes from its solid state to a liquid state, which is water. This change is purely physical because it only involves a change in the state of matter. The molecules of water in the ice rearrange themselves as they gain energy from the surrounding environment, causing the ice to melt into water. However, the chemical composition of the substance remains the same - it is still H2O, whether in the form of ice or water.

The process of melting ice is also reversible, which is another characteristic of physical changes. If the water is cooled, it will freeze back into ice. This reversibility further emphasises that no new substance is formed during the process.

Moreover, during this physical change, no energy is absorbed or released to break or form chemical bonds. The energy absorbed in this process is used to overcome the forces of attraction between the water molecules in the ice, allowing them to move more freely and transition into the liquid state. This is in contrast to a chemical change, where energy is absorbed or released to break old and form new chemical bonds, resulting in a new substance with different properties.

In conclusion, the melting of ice is a physical change because it involves a change in the state of matter from solid to liquid, without any alteration in its chemical composition. It is a reversible process that does not involve the formation or breaking of chemical bonds.