Question

State the main postulates of Dalton's Atomic theory. Explain how the modern atomic theory contradicted Dalton's Atomic theory.

Answer 1

Postulates of Dalton's atomic theory:-

• Matter is made up of extremely small individual and Indestructible ultimate particles called atoms.

• Atoms of the same elements are identical in all respects in same size mass and chemical properties.

• Atoms of different elements are different in all respects and have different masses and chemical properties.

• Atoms of two or more elements combine in a fixed ratio to form compound atoms known as molecules.

• Chemical reaction involves only combination separation arrangement of atoms.

• Atoms can neither be created nor destroyed during any physical or chemical change.

The Contradiction between Modern theory and Dalton's atomic theory.

• According according to the Delton atomic theory the atoms are indivisible but according to the Modern theory the atoms are indivisible into electron ,protons, and neutrons.

• According to Dalton's atomic theory the atom of same elements are identical but according to modern theory atoms of different elements cannot be identical known as isotope.

• according according to Delton atomic theory the matter can not destroyed but according to modern theory the matter is converted into energy.

Answer 2

Answer:

Acc. to it

☆Matter is made up of extremely small particles called atoms.

☆Atoms of same element are identical in size shape and atomic mass.

☆Atoms of different elements are different in all respect.

☆Atoms of same or different elements are combined together to form different compounds called molecules.

☆When atoms combined with each other to form molecules, they have simple or same multiple proportion.

Atoms can neither be created nor be destroyed.