Rutherford Atomic Model

The Rutherford model, also known as the Rutherford atomic model, the Nuclear atom or planetary atom was proposed by New Zealand physicist Ernest Rutherford in 1911.

In 1909, he used alpha particles to investigate the composition of gold foil.

The model described the atom as a small, dense, charitable compound called the nucleus, in which almost all of the residue is concentrated in the negative elements called electrons orbiting a certain distance like the planets orbiting the sun.

Rutherford model

• The model of plum pudding was provided by J. J. Thomson failed to explain certain experimental results associated with the atomic structure of matter. Ernest Rutherford, a British scientist who conducted the study and based on the observations of this study, proposed the atomic composition of the elements and presented the Rutherford Atomic Model.
• The Rutherford model shows that an atom is usually an empty space, with electrons surrounding a fixed nucleus, with positively charged in set, predictable pathways.

Rutherford alpha scattering experiment

• He did research by blasting a small sheet of gold with alpha particles.
• The trace of these particles was then studied after their contact with the gold plate.
• Direct the alpha energy from the radiation source to a thin sheet (100 nm thick) of gold.
• To study the deformation created by alpha particles he placed a fluorescent zinc sulphide screen around a small gold plate.
• He made some observations that contradicted Thomson’s atomic model.

Rutherford’s conclusion for the alpha scattering

• A chief fraction of the α-particles bombarded closer to the gold sheet surpassed through it without any deflection, and therefore most of the space in an atom is empty
• Some of the α-debris have been deflected by using the gold sheet via very small angles, and subsequently the effective price in an atom is not uniformly disbursed. The effective charge in an atom is concentrated to a completely small extent.
• Only a few of the α-debris have been deflected; only a few α-particles had an almost 180 degree angle of deflection. So, the quantity occupied by means of the positively charged particles in an atom may be very small in comparison to the total volume of an atom.
• He discovered most of the atom was empty space.
• Deviation of alpha particles was because of positive charges in the foil.

Disadvantages of Rutherford model

• It was not according to  Maxwell’s principle and could not give an explanation for the steadiness of an atom.
• He didn’t say anything about the electronic arrangement of atoms, which made his theory incomplete.
• Although early atomic models were inaccurate and could not explain the results of some experiments, they served as the basis for future developments in quantum mechanics.
• Charged particles during acceleration would give out energy while revolving around nucleus it will lose energy and fall down into the nucleus
• His model can’t explain hydrogen atomic spectra.
• It did not mention anything about electron arrangement in the orbit.
• Was unable to explain the scattering experiment of Rutherford.

Advantages of Rutherford model

• He discovered the presence of nuclei in atoms by his experiment.
• He imagined electrons revolving around the nucleus like planets around the sun.
• He assumed most of the atoms were hollow.
• This model was able to explain the gold foil experiment And answers the question why atoms are known to be electrically neutral.
• Postulated nuclear structure of the atom.

Conclusion

The conclusions were drawn from Rutherford scattering experiments. Most alpha particles flew straight without deviating. So there was nothing to stop them along the way. This means that most of the space in the foil is free and you can see the core.