Question

Write down two difficulties of Rutherford’s atomic model.

Hint:

Rutherford’s model laid the foundation for modern atomic theory, but it was unable to explain the stability of atoms and the spectral lines observed in experiments.

Answer 1

Step 1: Difficulty 1 – Stability of the Atom.
In Rutherford’s model, the electrons orbit the nucleus in circular paths. According to classical electromagnetism, an electron in motion should radiate energy in the form of electromagnetic waves. This would cause the electron to lose energy, spiral inward, and eventually crash into the nucleus. Hence, the atom should not be stable, but it is. This is a major difficulty of Rutherford’s model.
Step 2: Difficulty 2 – Discrete Line Spectra.
Rutherford’s model could not explain the observed discrete line spectra of atoms. According to the model, electrons would emit a continuous spectrum as they lose energy, but experimentally, only specific wavelengths (discrete lines) were observed in the atomic spectra. This discrepancy led to the development of a new model by Niels Bohr.
Final Answer:
1. Stability of the atom (electrons should spiral into the nucleus).
Failure to explain the discrete line spectra of atoms.