Drawbacks of Rutherford model of an atom are .
1. an electron moving in a circular orbit is not said to be stable .
2. when electron move it radiates energy
3. an electron go on acceleration and finally fall into nucleus .
so this can't said to be stable ,it is unstable

Thomson's atomic model, also known as the plum pudding model or the raisin bun model, has several drawbacks:

1. Lack of a dense nucleus: Thomson's model proposed that the positive charge and electrons were evenly distributed throughout the atom, resembling a plum pudding or a raisin bun. However, later experiments, such as the gold foil experiment by Ernest Rutherford, showed that the positive charge is concentrated in a small, dense nucleus at the center of the atom. Thomson's model failed to account for this.

2. Failure to explain the stability of the atom: Thomson's model did not address why electrons, which are negatively charged particles, do not simply collapse into the positively charged nucleus. It did not provide an explanation for the stability of the atom or the existence of different energy levels for electrons.

3. Lack of atomic structure: The plum pudding model did not propose the existence of specific energy levels or orbitals for electrons. It did not explain how electrons are arranged around the nucleus or why certain energy levels are filled before others. It also did not account for the concept of electron shells.

4. Inability to explain spectral lines: Thomson's model was unable to explain the observed spectral lines in atomic emission or absorption spectra. These lines are a result of transitions between specific energy levels of electrons, which were not accounted for in the plum pudding model.

5. Failure to explain isotopes: Thomson's model did not account for the existence of isotopes, which are atoms of the same element with different numbers of neutrons. It did not provide an explanation for the variation in atomic mass observed in different samples of the same element.

Overall, while Thomson's atomic model was a significant step in understanding atomic structure, it had several drawbacks and was eventually replaced by more accurate models, such as Rutherford's nuclear model and Bohr's model of the atom.