Rutherford’s Experiment

Rutherford’s Experiment

In 1911, Lord Rutherford bombarded a gold foil with a beam of α-particles (an α-particle is a positively charged helium ion - He2+). He observed that:

(i)Most of the α-particles passed straight through the foil.

(ii)Some were deflected away from the path near the centre.

(iii)A few were reflected back.

On the basis of the results of alpha -Scattering experiment, Rutherford proposed that

(i)Atom is spherical.

(ii)Most part of the atom is empty.

(iii)Mass and positive charge of the atom are located at the centre of the atom i.e. in the nucleus.

(iv)Electrons move around the nucleus in circular paths.

The attractive force between the positively charged nucleus and negatively charged electron is balanced by the centrifugal force.

Drawback of Rutherford model of an atom

Rutherford’s model, however, fails to explain the stability of atoms and the line spectrum of hydrogen