dalton atomic theory

“DALTON’S ATOMIC THEORY”

WHO WAS DALTON?John Dalton FRS (6 September 1766 – 27 July 1844) was an English chemist, meteorologist and physicist. He is best known for his pioneering work in the development of modern atomic theory, and his research into colour blindness

WHAT IS DALTON’S ATOMIC THEORY?

A theoretical proof the validity of different laws was given by John

Delton in 1808,in the form of a model of an atom known as Dalton’s Atomic

Theory.

POSTULATES OF DALTON'S ATOMIC THEORY

I. POSTULATE

Matter is made up of extremely small particles called atoms.

II. POSTULATE Atoms are indivisible particles, which can neither be created nor destroyed in an chemical reaction .

III. POSTULATEAtoms of given element are identical in all respects of mass, shape, size, and chemical properties.

IV. POSTULATE Atoms of different elements have different masses and chemical properties .

V. POSTULATE Atoms of same or different elements combine together to form compounds.

VI. POSTULATE•The relative number and kinds of atoms are constant in a given compound.

DRAWBACKS OF DALTON'S

ATOMIC THEORY

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• According to Dalton’s theory, atoms of same element have same mass but this

theory does not hold good in case of isotopes of an element.

I.DRAWBACK

13

• According to Dalton’s theory, atoms of same element have same mass but this

theory does not hold good in case of isotopes of an element.

II.DRAWBACK

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Allotropic forms of the same compound posses different

properties. For example, diamond, graphite and charcoal are all forms of carbon but their properties are different from one another which prove that all atoms of the same element are not identical in every

isobars.

III.DRAWBACK

• According to Dalton’s atomic theory, the masses of different elements are different but theory does not hold good in case of isobars.

IV. DRAWBACK

THANK YOU

THE END

EFFORTS BY:

KARNIK SINGH

CLASS: IX-A ROLL NO-26