CBSE
Class 10
Class 12
The following two laws of the chemical combination were established by Lavoisier and Joseph L. Proust.
In a chemical reaction, the total mass of product is equal to the total mass of the reactant.
"In other words, mass neither be created nor be destroyed in a chemical reaction."
"In a chemical substance, the elements are always present in definite proportions by mass”.
Postulates of Dalton’s atomic theory