A calcium supplement tablet has a total mass of 1.35 g1.35\text{ g}1.35 g and contains 450 mg450\text{ mg}450 mg of calcium carbonate as the active ingredient.
Tablets are examples of mixtures designed with exact quantities of specific substances to serve a particular function. What term is used to describe this type of mixture?
Calculate the percentage by mass of calcium carbonate in this tablet. Show your working and give your answer to 3 significant figures.