Answer:
The law of conservation of mass states that in a closed system, mass is neither created nor destroyed during a chemical or physical reaction. The law of conservation of mass is applied whenever you balance a chemical equation.
Step-by-step explanation:
According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.
The law of conservation of mass is useful for a number of calculations and can be used to solve for unknown masses, such the amount of gas consumed or produced during a reaction.
It is applicable in a chemical when the the mass of the products in a chemical reaction is equal to the mass of the reactants.
But it is not applicable in a nuclear fusion as some of the mass is generated as energy.