Question

State the difficulties faced by Rutherford’s atomic model.

Answer 1

1. An electron in Rutherford’s model moves uniformly along a circular orbit around the nucleus. Even though the magnitude of its velocity is constant, its direction changes continuously and so the motion is an accelerated motion. Thus, the electron should emit electromagnetic radiation continuously. Also, as it emits radiation, its energy would decrease and consequently, the radius of its orbit would decrease continuously.
2. It would then spiral into the nucleus, causing the atom to collapse and lose its atomic properties. As the electron loses energy, its velocity changes continuously and the frequency of the radiation emitted would also change continuously as it moves toward the nucleus. 
3. Firstly, most atoms are very stable and secondly, they do not constantly emit electromagnetic radiation and definitely not of varying frequency. The atoms have to be given energy, e.g., by heating, for them to be able to emit radiation and even then, they emit electromagnetic radiations of particular frequencies as will be seen in the next section. Rutherford’s model failed on all these counts.