Which type of change can be reversed without creating a new substance?

A physical change involves alterations in the form, state, or appearance of a substance without changing its chemical composition. This means that the substance can return to its original state without any new substances being formed. For example, melting ice into water is a physical change; if you freeze the water again, it becomes ice without any chemical transformation occurring.

In contrast, a chemical change results in the formation of one or more new substances, indicating a permanent alteration in the chemical structure. Processes such as combustion or fermentation exemplify chemical changes, as they cannot be easily reversed.

Endothermic and exothermic changes refer to specific types of chemical reactions based on heat absorption or release, respectively. Both of these involve chemical changes where new substances are formed and, therefore, cannot be reversed without resulting in a substantial change in composition. Thus, the key characteristic of physical changes—being reversible without creating new substances—makes this option the correct choice.