A student investigates what happens to different substances when they are heated and then allowed to cool. Their observations are recorded in the table below.
| Substance | State and appearance before heating | State and appearance when hot | State and appearance after cooling |
|---|---|---|---|
| Glass bead | Solid (clear) | Solid (clear) | Solid (clear) |
| Paraffin wax | Solid (white) | Liquid (clear) | Solid (white) |
| Pancake batter | Liquid (pale yellow) | Solid (golden brown) | Solid (golden brown) |
Explain how we know the change to the pancake batter is a chemical change rather than a physical change.
