Which of these is an indication that a chemical reaction has occurred?

A. Melting of a substance
B. A change of color in a substance
C. Boiling of a substance
D. Freezing of a substance

Respuesta :

The following indication that a chemical reaction has occurred would be B. A change in colour in a substance. The other 3 are physical changes.

The correct answer is B. A change of color in a substance

I took the test as well and that was the right one.