List 3 signs or indicators that a chemical reaction has occurred.
1 point for each correct sign that is listed.
1. Formation of a solid (precipitate): If a chemical reaction has occurred, there may be a visible formation of a solid substance in the reaction mixture.
2. Change in color: Chemical reactions often involve a change in color. The appearance of a new color or a significant change in the intensity of an existing color may indicate a chemical reaction.
3. Evolution of gas: Production of gas bubbles or a noticeable release of gas during a reaction is a clear indication that a chemical reaction has taken place. This is often observed through effervescence or bubbling in the reaction mixture.