What describes a physical change?

A physical change is characterized by alterations in physical properties such as size, shape, or state of matter, without affecting the chemical composition of the substance. For example, when ice melts into water, the solid (ice) changes into liquid state (water), but the chemical composition of water (H₂O) remains unchanged.

This definition highlights that during a physical change, the substance's molecular structure and identity are maintained, allowing it to revert to the original state if needed. In contrast, the other options describe scenarios that do not align with this fundamental principle of physical change. Some involve chemical transformations, such as altering the composition of a substance or involving reactions that produce new substances like gas or precipitate, or processes that inherently absorb heat, which are indicative of chemical changes or other processes.