What defines a physical property of matter?

A physical property of matter is defined by characteristics that can be observed without altering the substance's composition. This means you can assess these properties like color, density, boiling point, and texture without changing the chemical structure of the material itself. For example, measuring the melting point of ice does not change it chemically; it simply transitions from solid to liquid form, which is still water.

This understanding is fundamental in science because it allows for the classification and differentiation of materials based solely on their observable traits, aiding in identifying substances and predicting their behavior under different conditions. The other options reflect observations that involve changes to the substance, specifically related to chemical processes or conditions that are not relevant to defining physical properties.