Once all safety equipment is in place, each student places a piece of aluminum foil into a test tube of hydrochloric acid. After a few seconds, the aluminum foil disappears and the bottom of the test tube feels hot. The balanced chemical reaction demonstrated in the investigation is shown below. 6HCl + 2Al à 3H2 + 2AlCl3

What evidence of a chemical reaction should the students cite for this investigation?
F. Change in color
G. Production of a gas
H. Increase in temperature
J. Formation of a precipitate