Dalton's atomic theory was the first complete attempt to describe all matter in terms of atoms and their properties. Dalton based his theory on the law of conservation of mass and the law of constant composition. The first part of his theory states that all matter is made of atoms, which are indivisible.

He said that All matter is made up of very small particles called atoms ...
Atoms cannnot be divided
Atoms can neither be created nor be destroyed.

Dalton's Atomic Theory and the Law of Conservation of Mass

The law of conservation of mass states that in a chemical reaction, the total mass of the reactants is equal to the total mass of the products. This law holds true even if the substances undergo physical or chemical changes. Dalton's atomic theory provides a clear explanation for this fundamental principle of chemistry.

Dalton's Atomic Theory

1. Atoms are indivisible and indestructible: According to Dalton, atoms are the fundamental building blocks of matter, and they cannot be divided into smaller particles or destroyed during a chemical reaction.

2. Atoms of the same element are identical: Dalton proposed that all atoms of the same element are identical in mass, size, and other properties. This means that the mass of an atom of a particular element remains constant throughout a chemical reaction.

3. Atoms combine in simple, whole number ratios: Dalton suggested that atoms combine to form compounds in fixed ratios. This means that the number and types of atoms involved in a chemical reaction remain constant.

4. Chemical reactions involve the rearrangement of atoms: According to Dalton, chemical reactions occur when atoms are rearranged to form new compounds. However, the total number of atoms before and after the reaction remains the same.

Explanation of the Law of Conservation of Mass

The law of conservation of mass can be explained by Dalton's atomic theory as follows:

1. Mass of reactants: In a chemical reaction, the reactants consist of atoms that are rearranged to form new compounds. Dalton's theory states that the atoms themselves are not created or destroyed during the reaction. Therefore, the total mass of the reactants remains constant.

2. Mass of products: Similarly, the products formed by the rearrangement of atoms have the same total mass as the reactants. This is because the atoms simply change their arrangement to form new compounds, without any change in mass.

3. Conservation of mass: The law of conservation of mass states that the total mass of the reactants is equal to the total mass of the products. Dalton's atomic theory supports this law, as it indicates that atoms are the fundamental units of matter and their mass remains constant during chemical reactions.

Conclusion

Dalton's atomic theory provides a comprehensive explanation for the law of conservation of mass. According to the theory, atoms are indivisible and indestructible, and they combine in fixed ratios to form compounds. Therefore, the mass of the reactants and products in a chemical reaction remains constant, supporting the principle of mass conservation.