CoachA physical transformation changes the state or the arrangement of matter without changing the chemical species: melting, freezing, boiling, dissolving, mixing. The same species are present before and after; only their form or their arrangement has changed.
Examples
Example 12.2 (Water, three ways)
Ice melting into water, water boiling into water vapour, and salt dissolving in water are physical transformations: before and after, there are water molecules (and salt). Zooming in, the molecules are the same; only how they are arranged and how they move has changed.