A change is a chemical change when it is accompanied by:A.energy changeB.formation of new substancesC.change in chemical propertiesD.All of the above

To determine if a change is a chemical change, we need to consider the following factors:

1. Energy change: Chemical changes often involve the absorption or release of energy. This can be in the form of heat, light, or electricity. If there is a noticeable energy change during the process, it suggests a chemical change.

2. Formation of new substances: In a chemical change, new substances are formed. This means that the original substances are transformed into different substances with different properties. If there is evidence of new substances being produced, it indicates a chemical change.

3. Change in chemical properties: Chemical changes involve a change in the chemical properties of the substances involved. This can include changes in color, odor, taste, or the formation of gas or precipitate. If there is a noticeable change in the chemical properties, it suggests a chemical change.

Therefore, the correct answer is D. All of the above. A chemical change is accompanied by an energy change, the formation of new substances, and a change in chemical properties.