Oxygen atoms Hydrogen atoms

DALTON’S ATOMIC THEORY

1) All matter is composed of tiny, indivisible particles called atoms. For example, atoms of oxygen.

2) All atoms of a particular element are identical, but the atoms of one element differ from the atoms of any other element. Each element has unique atoms.

3) Atoms of different elements combine with each other in certain whole-number proportions to form compounds. For example, water (H2O) is a combination of one atom of oxygen and two atoms of hydrogen.

4) In a chemical reaction, atoms are rearranged to form new compounds; they are not created, destroyed, nor changed into atoms of any other element.

There were three fundamental laws established by Dalton and other scientists of his time to support the atomic theory. These laws are the:

a) Law of Conservation of Mass

The law of conservation of mass states that in a chemical reaction, matter is neither created nor destroyed, or, more accurately, there is no detectable change in mass during an ordinary chemical reaction.

b) Law of Definite Proportions

The law of definite proportions states that different samples of any pure compound contain the same elements in the same proportions by mass.

c) The Law of Multiple Proportions

 • Oxygen•Carbon•Hydrogen

The law of multiple proportions states that the mass of one element that can combine with a fixed mass of another element are in a ratio of small whole numbers.