Question

The interconversion of a substance from one state of matter to another is an example of a ___ change.

Answer 1

The interconversion of states is a physical change because these changes occur without change in composition and the chemical nature of the substance. Although ice, water and water vapour all look different and display different physical properties, they are all chemically the same substance. This is because the chemical formula of ice and water vapour both are ${\text{H}}_2\text{O}$.