Question

formation of a solid, formation of a gas, and a color change can also occur during some physical changes. give examples of physical changes that could produce these clues. what evidence suggests that the changes you observed in test tubes 1-3 were, in fact, chemical changes

Answer 1

Examples of these physical changes are melting ice-cream, or boiling water as well as freezing it. Adding dye to water is also a physical change since the chemical compounds remain the same, it is only the physical appearance that changes.

Possible reasons for chemical changes are the formation of a precipitate (solid), or formation of gas (bubbling) as well as release of heat or light or release of odor.