Question

What does conserving mass mean in a chemical equation?

Answer 1

The answer is C. There is equal number of each type of atom on the reactant side and product side.

I just did test!

Hope it helps :)

Answer 2

I would say that what conserving mass in a chemical equation means is that C. There is equal number of each type of atom on the reactant side and product side.
The equation is equal and no material is lost or gained.