Question

(a) What are cathode rays? What is the nature of charge on cathode rays?
(b) Explain how, cathode rays are formed from the gas taken in the discharge tube.
(c) What conclusion is obtained from the fact that all gases form cathode rays?

Answer 1

(a) In J.J Thomson experiment, he passed high voltage electricity through a gas in a discharge tube. Stream of minute particles were emitted by the cathode and those particles were called cathode ray. They consist of small negatively charged particle called electrons.

(b) When high voltage electricity is passed through a gas taken in a discharge tube, stream of minute particles are given out by the cathode. This happens because the gas taken in the discharge tube consists of atoms and contains electrons. These electrons are excited when electricity passed. These free fast moving electrons are cathode rays.

(c) Formation of cathode rays show that one of the subatomic particles presents in all atoms is the negatively-charged electrons.