help me, please. What science law explains why there should always be the same type of elements on the reactant side as there are on the product side? What does this law state? (HINT: Answer both of these questions. A: The Law of states that .)

Awhite powder is added to a solution. the images show observations made before the powder is added, just after the powder has been added, and a little while later. (the liquid in the small beaker is phenol red solution.) what evidence shows that a chemical change has taken place?