Question

How is Thomson’s model of an atom different from Dalton’s model?

Answer 1

Hint: Dalton’s atomic theory proposed that all matter is composed of atoms which are indivisible and indestructible.Thomson’s model of an atom states that an atom comprises electrons distributed between a sea of protons in the same fashion as seeds in a watermelon/plum.

Complete answer:
> According to Dalton’s atomic theory, the smallest and the ultimate particle of matter is known as an atom. Atoms of the same element are alike in all respects while atoms of different atoms are not the same. Dalton did not talk about the internal structure of the atom in his theory.
> However, it was made clear after Thomson's model that atoms are not as simple as suggested by Dalton. The atom is made up of a number of particles like protons and electrons.
> In Thomson’s model of an atom, he proposed that an atom may be regarded as a sphere of approximate radius of ${10^{-8}}$ cm carrying positive charge due to protons in which negatively charged electrons are embedded or studded. This model is also known as Thomson’s plum pudding model since it is just like raisins in pudding.

Additional information:
- The first evidence-based theory about atoms was given by Dalton in his Dalton’s atomic theory.
- The Thomson’ model of an atom did not have any experimental evidence in its support and was therefore rejected.

Note: The basic difference between the two models lies in the fact that Dalton proposed that an atom was indivisible and indestructible whereas Thomson worked on the existence of subatomic particles inside an atom and their arrangements i.e., he considered an atom to be a divisible quantity unlike Dalton.