Formation of frost on a cold night is an example of which type of change?

The formation of frost on a cold night is indeed a physical change. This process occurs when water vapor in the air loses energy as the temperature drops, allowing the water molecules to transition directly from a gaseous state to a solid state in a process known as deposition. During this transition, the chemical composition of the water molecules (H2O) remains unchanged, as no new substances are created; therefore, it is classified as a physical change.

Physical changes involve changes in the state or appearance of a substance without altering its chemical structure. In the case of frost, while the water vapor transforms into solid ice crystals, the fundamental compound of water does not change. The conditions that lead to the formation of frost—such as temperature and humidity levels—can cause these physical changes without any chemical reactions occurring.

This distinction is key in understanding the nature of physical versus chemical changes. Chemical changes involve the making or breaking of bonds, resulting in new substances forming, whereas physical changes are simply adjustments in form or state.