Question

4a what event is occurring? 4b circle chemical change or physical change

Explanation:

A chemical change results in a new substance with different properties. Here, adding a white - powder to a red substance and getting a blue substance indicates a chemical reaction has occurred, forming a new substance with a different color. In a physical change, the substance's identity remains the same, just its physical state or appearance changes slightly. Since a new substance with a different color is formed, it is a chemical change.

Answer:

4a. A chemical reaction is occurring.
4b. Chemical Change