Question

change in a substance that does not alter its composition
physical change
law of conservation of mass
observation
chemical change

Explanation:

A physical change is a transformation in a substance that does not change its chemical composition. For example, melting ice into water is a physical change as both ice and water are H₂O. The law of conservation of mass is about mass remaining constant in a chemical or physical process. Observation is a method of gathering data. A chemical change results in a new substance being formed. So the term for a change in a substance that does not alter its composition is physical change.

Answer:

physical change