Question: The production of a gas

Answer: This happens with two reactants (substance that undergoes change) combine, bubbles form indicating the production of CO2.

Question: Change of Color

Answer: *Many times when the Ph of a solution changes, the color changes.

Question: A change in temperature

Answer: When two substances of the same temperature react with one another it can cause a change in temperature. The temperature change can be either an increase(+) or a decrease(-).

Question: Production of light

Answer: When a substance rapidly combines with oxygen-combustion occurs and a flame is produced that gives off thermal energy and light.

Question: Precipitate forms

Answer: A precipitate is an insoluble compound formed out of a solution.