what is John Dalton theoty.

Failure of Dalton’s Atomic Theory The postulates of the atomic theory by John Dalton • The matter is made up of tiny particles called Atoms that cannot be divided. • Atoms are never formed or destroyed during a chemical reaction. • Atoms of an element exhibit same nature. They have the same size, mass, and character. • Atoms of different elements exhibit variant nature. They do not have same characteristics. • Atoms form compounds by combining in a ratio of whole numbers. • A compound contains a constant number and kinds of atoms Dalton suggested that atoms can neither be created nor destroyed and are indivisible. But the discovery of electrons and protons in atoms lead to failure of this aspect of Dalton’s theory.

The postulates of this theory may be stated as follows:

• Matters are composed of very tiny particles called atoms.
• These particles are too small to see and cannot be created or destroyed in a chemical reaction.
• Atoms of a specified element are identical in mass and chemical properties.
• Atoms of different elements have different masses and chemical properties.
• Atoms combine in the ratio of small whole numbers to form compounds.
• The relative number and kinds of atoms are constant in a given compound.

John Dalton's atomic theory says tht all things in the universe whether an element or a compound or a mixture is made up of an unknown seen form of matter that is the atom . Atom is the smallest particle of matter. It is the basic unit of all. It is indivisible and thus cannot be divided