What does conserving mass mean in a chemical equation?

There are more of each type of atom on the product side than on the reactant side.

There are more of each type of atom on the reactant side than on the product side.

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

There is an unequal number of each type of atom on both sides of the equation.

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

Explanation:

Conserving mass in a chemical reaction means  balancing the conservation of mass through  the law and balancing the atoms. There is equal number of each type of atom on the reactant and product side.

There is an equal amount of atoms on both the sides that is the reactant side as well as the product side, it balances the atoms to have a conservation of mass, through the law of conservation of mass.

Using the law of conservation mass, a chemical reaction is balanced and has a conserved mass, when the reactant and the product side contain equal atoms.

we need answer choices

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.