Question

From the discharge tube experiment, it is concluded that:
A. Mass of proton is in fractions
B. Matter contains electrons
C. Matter contains Nucleus
D. Positive rays are heavier than protons

Answer 1

Hint: Discharge tube experiments were conducted extensively by Faraday and later by J.J. Thomson. One should recall that he was trying to find out more about the deposit of matter at the electrodes of his experiments, which suggested the particulate nature of electricity.

Complete Step by Step Solution:
Let us talk about the discharge tube experiment first.
J.J. Thomson during his experimental days was trying to study the electrical discharge in partially evacuated tubes which are termed as cathode ray discharge tubes.
A cathode ray tube is essentially made up of glass containing two thin pieces of metal called electrodes.
The discharge could be observed only through low pressure and very high voltage, the pressure is in turn dependent on the nature of the gas which could be adjusted through the evacuation tubes.
At a certain sufficiently high voltage, a stream of particles moving in the tube from the negative electrode (cathode) to the positive electrode (anode). These were cathode rays.
In the presence of an electrical or magnetic field, the behaviour of cathode rays are similar to that expected from negatively charged particles suggesting that the cathode rays consist of negatively charged particles, called electrons.
Through this it was concluded that electrons are basic constituents of all the atoms thereby matter contains electrons.
Hence, through the above experiments it could be concluded that the matter containing electrons are conclusively proven through the discharge tube experiment. Therefore the correct answer is B.

Note: Don’t confuse it with the fact that Faraday initially performed the discharge tube experiment but J.J. Thomson successfully performed the experiment and proved that atoms contain negatively charged particles, which he called electrons.