Question

Which of the following are evidence that a chemical reaction has occurred?

A. Two liquids are combined and a gas is released
B. A substance is added to water and dissolves
C. Two liquids are combined and a solid precipitate forms
D. A new substance is formed
E. A single reactant changes from a liquid to a solid

Answer 1

A, B and C

Step-by-step explanation:

The 7 rules of chemical change....

Gas Bubbles Appear. Gas bubbles appear after a chemical reaction has occurred and the mixture becomes saturated with gas. ...

Formation of a Precipitate. ...

Color Change. ...

Temperature Change. ...

Production of Light. ...

Volume Change. ...

Change in Smell or Taste.