Answer 1

Postulates of Dalton's atomic theory of matter :

• Matter comprises very small particles called atoms.
• Atoms of different elements differ in mass, size and chemical properties.
• Atoms can neither be created nor destroyed.
• Chemical reactions involve the combination, separation or rearrangement of atoms to form molecules or compounds.
• Atoms cannot be divided.
• A compound has a fixed number and kind of atoms.
• Atoms of the same element can combine in more than one ratio to form more than one compound.
• All the atoms in an element are identical in every aspect i.e. they have same mass, size and chemical properties.
• Like elements, there are many kinds of atoms.
• Atoms of different elements join together to form molecules of the compound in a chemical combination.