Which statement accurately describes a physical change?

A physical change refers to a modification that does not alter the chemical composition of a substance, meaning that while its appearance or state may change, the identity of the substance remains the same. For instance, when ice melts into water, the water is still H2O, just in a different form. This characteristic of physical changes distinguishes them from chemical changes, which involve the formation of new compounds with different properties.

The idea that a physical change can involve a change in form—such as transitioning from solid to liquid to gas—without affecting the substance's fundamental identity is critical. This allows us to recognize scenarios like dissolving sugar in water or breaking glass, where the chemical structure of the substances involved does not change even though their physical state or condition might differ.

Regarding reversibility, it's important to note that while many physical changes are reversible (like freezing and melting), not all are. For example, cutting a piece of paper or crushing a can are physical changes that might not be easily reversed. However, this alone does not define physical change, making it an incomplete criterion. Thus, the statement about changing the form without altering identity accurately encapsulates what constitutes a physical change.