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

Responses

monitor for the release of a gas

observe a color change

conduct a test to determine the chemical makeup of the molecules

test for the release of heat

Answer 1

All of the options provided can indicate a chemical change, but some are more reliable than others.

1. Monitor for the release of a gas: This is a common indication of a chemical change, especially if gas was not present before the reaction.

2. Observe a color change: A color change often signifies that new substances have formed, which is a reliable indicator of a chemical change.

3. Conduct a test to determine the chemical makeup of the molecules: This is more a method of analysis rather than direct observation, and typically required post-reaction to confirm a change.

4. Test for the release of heat: This can indicate a chemical change as well, but similar to gas release, it can also depend on environmental conditions and the specific reaction involved.

Among these options, observe a color change would generally be regarded as a reliable and immediate way to conclude that a chemical change has occurred when two substances come into contact.