Question

During science lab, some students added small pieces of magnesium ribbon to 10 mL of hydrochloric acid. They noticed that bubbles formed, the test tube got hot, and the magnesium disappeared.

Which is a sign that a chemical reaction has taken place in this experiment?

Answer 1

Your answer would be a change in odor! Hope this helps! ;D

Answer 2

C

Step-by-step explanation:

Release of heat energy

The test tube got hot; that's a sign that heat energy is being released. This is an exothermic chemical reaction. Change in odor and color are signs of a chemical change but do not occur in this case.

(Correct in USA Test Prep too!)