The
Law of Conservation of Mass simply states that
matter cannot be
created nor
destroyed. The
law was first introduced to the world by
Antoine Laurent Lavoisier (1743-1794), the "
Father of Modern Chemistry", by showing
conservation of mass in
chemical reactions.
The law can be taken further in that:
Mass of All Reactants = Mass of All Products;
Matter cannot be created from nothing, it can only change its form during chemical reactions.
See: Material Balances and conservation laws