Rutherford’s Nuclear Model of Atom:
Rutherford’s nuclear model of atom is given as follow:
1. Atom is very small, spherical and electrically neutral particle containing maximum, empty part.
2. In an atom, the entire mass and positive charge is concentrated in a very small region at the centre, known as nucleus.
3. The nucleus of atom is positive because all positive charge of atom i.e, all protons are situated in nucleus.
4. Atom is electrically neutral. Hence number of proton present in atom in equal to the number of electron present in atom.
5. The circular path in which electron move around the nucleus is called orbit
6. The positively charged nucleus imposes attraction force on electron but it does not fall into nucleus because the centrifugal force produced by rotation of electron balance the attraction force of nucleus. Size of nucleus is very small as compared to size of atom. Nucleus is about 10-15 th part of atom and its radius is proportion to cubic root of nucleons (proton + neutron) present in atom
Limitations of Rutherford’s Model:
The coulomb force between nucleus and electron is equal to gravitational force in mathematical form.
where q1 and q2 are charges
r is distance between q1 and q2
K is proportionality constant
The Rutherford model of atom resembles the solar system in which planets rotate around sun. But there are some short comings in this model, these are given as-
1. It was not able to explain the stability of atom.
2. It does not explain the spectrum of hydrogen and other atoms.
3. This model could not explain the distribution of electron.
