d. 6 grams
The Law of Conservation of Mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. Meaning that, the amount of mass cannot change. So, the mass in the reactant must be equal to the amount of mass in the product. We had 6 grams of mass in the beginning, and it will not change. That means we'll have 6 grams in the end as well.
D. 6 grams is the answer
