Which of the following is a reliable way to observe that a chemical change has occurred when two substances come in contact with one another?(1 point)

Question

observe a color change
observe a color change

monitor for the release of a gas
monitor for the release of a gas

test for the release of heat
test for the release of heat

conduct a test to determine the chemical makeup of the molecules

Answer 1

observe a color change
monitor for the release of a gas
test for the release of heat