Respuesta :
change in color, increase of temperature, formulation in bubbles
Answer:
It C. change in density (I WAS INCORRECT ON PLATO TEST IT IS NOT C)
Explanation:
"To definitively determine that a chemical reaction has taken place, it is necessary to carefully test the properties of reactants and products. Each substance has a unique set of properties. One of them is density. We can determine whether two substances are the same or different by calculating and comparing their densities. No two substances in their purest form have the same density." this is from my plato science notes