After two elements react to completion in a closed container, the ratio of their masses in the container will be the same as before the reaction. Which law describes this principle

law of conservation of mass

Explanation:

Law of conservation of mass -

This law was given by the father of chemistry, Antoine Laurent Lavoisier.

According to this law,

The mass of the system remains constant, i. e., mass can neither be created nor be destroyed, is known as the law of conservation of mass.

In a chemical reaction, the mass of the reactant always equalizes with the mass of the product.

Hence, from the given information of the question,

The correct term is the law of conservation of mass.