PLS HURRY 50 PTS AND BRAINLIEST Which of the following statements represent the law of conservation of mass?

A. The mass of the reactants is not equal to the mass of the products.
B. The mass of the new compounds is not equal to the mass of the materials before the reaction started.
C. The mass of the reactants is equal to the mass of the products.

Why does the system need to be closed to prove conservation of mass?

A. If a system is open that means matter can escape or be introduced.
B. If a system is open gases will not escape.
C. If system is open escaped gases do not change the amount of matter enough to change the amount of mass.