Question

What is the law that states that mass cannot be created or destroyed in ordinary chemical and physical changes?

Answer 1

This is known as...The Law of Conservation of Mass (and it relates to all chemical and physical changes).

Explanation:

Credit for stating the law of conservation of mass generally goes to Antoine Lavoisier in the late 18th century, although several others had worked on the idea prior to him. The law was vital to the development of Chemistry because it led to the overthrow of phlogiston theory and to rapid advances in the late 118th and early 19th centuries in the law of definite proportions and ultimately to Dalton's atomic theory.