Question

1. when differentiating between chemical and physical properties of matter, the identity of the ____ must be changed.
2. this is a substance that takes part in and undergoes change during a reaction.
3. this is a substance that is formed when two or more chemicals react.

Explanation:

1. Chemical properties involve a change in the substance's identity at the molecular - level.
2. A reactant is a substance that participates in and changes during a reaction.
3. A product is a substance formed when two or more chemicals react.

Answer:

1. Substance
2. Reactant
3. Product