PLS HELP I NEED TO PASS THIS... In physical science lab, Kim and Dawn added small pieces of magnesium to hydrochloric acid. They observed that bubbles formed, the test tube got hot, and the magnesium disappeared. What is a sign that a chemical reaction has taken place in this experiment?
Question 7 options:
A.odor
B.gas is produced
C.temperature decreased
D.magnesium appeared