Chemistry

Rutherford’s Atomic model : The main features of Rutherford’s model of an atom are :
The atom consists of a positively charged centre called the nucleus.
Most of the mass of the atom is concentrated in the nucleus.
The volume of the nucleus is very small as compared to the total volume of the atom.
The nucleus is surrounded by the negatively charged electrons. the electrons balance the positive charge of the nucleus. Therefore, the number of electrons in an atom is equal to the number of protons in it.
The magnitude of the positive charge on the nucleus is different for different atoms.
The electrons are not stationary but they are revolving around the nucleus at very high speeds like planets revolving around the sun. As a result, the electrons are also known as planetary electrons.
Drawbacks of Rutherford’s model :
Rutherford model failed in view of electromagnetic theory given by Maxwell. According to this theory a charged particle when accelerated emits energy in the form of electromagnetic radiation. According to Rutherford’s model, electrons are revolving around the nucleus. This means, electrons would be in a state of acceleration all the time. Since electrons are charged particles, therefore, electron revolving in an orbit should continuously emit radiations. As a result of this, it would slow down and would no longer be able to withstand the attractive force of the nucleus. Hence, it would move closer and closer to the nucleus and would finally fall in the nucleus by following a spiral path. This means atom would collapse. But actually we know atom is stable. Thus, Rutherford’s model failed to explain stability of atoms.