Question

Which of the following is not a clue that a chemical reaction has taken place? *

4 points
A solid is formed when two clear solutions are mixed.
A clear solution is added to a red solution, and the result is a blue solution.
A solid is added to water and bubbles form.
A pure solid is heated and turns into a pure liquid.

Answer 1

A pure solid is heated and turns into a pure liquid.

Step-by-step explanation:

No colour change recorded, only change of state, hence this is a physical change - physical changes I.e. change of state and temperature are not chemical reactions.