Chapter 3, Problem 1Q

To determine

The reason that prevented H. Hertz from discovering the character of electrons.

Answer to Problem 1Q

The ionization of the gas led to the formation of ions in the cathode ray tube due to which the correct observation could not be made about the nature of the electron.

Explanation of Solution

The experiment performed by H. Hertz to determine the nature of electron was dependent on the behaviour of electron under the electric field. The cathode rays were passed through a tube and the electric field was present inside the tube to observe the effect on the cathode rays.

But the cathode ray tube used in the experiment was not completely evacuated. There was some amount of air present in the cathode ray tube. This air was ionised by the high energy cathode rays and several ions were formed. These ions were affected by the electric field and due to this; the correct observations about the character of the electrons could not be made. If the tube had been evacuated or it has been complete vacuum, there would be no ionization of the gas.

Therefore, the ionization of the gas in the cathode ray mixed up the result of the actual nature of the electrons with the result of the electric field on the ions of the gases. So, H. Hertz could not make the correct discovery about the nature of the electrons.

Conclusion:

Thus, the ionization of the gas led to the formation of ions in the cathode ray tube due to which the correct observation could not be made about the nature of the electron.