Describe the discovery of cathode rays.

1)The cathode rays are made up of material particles. 2)They carry -ve charge. Hence, the above experiment explains that, cathode rays are negatively charged material particles called as ELECTRONS.

Cathode Ray Experiment: This is also known as discharge tube experiment , because it was initially done in a discharge tube .This experiment was carrried out by Willium Crookes in 1879 to explain the properties of negatively charged particles and conduction of electricity through gases in low pressure. Latter, the experiment was used by J.J Thomson to explain the nature of electron and discovery of electron. Mr. Cookes , studied that, electricity can be conducted through gases when at low pressure. Experiment: According to the above theory, a discharge tube (which is a long glass tube) is taken about 60cm long and sealed that tube at both the ends and fitted with two metal electrodes. It has a side tube fitted with a stop - ****. Now , this tube is connected to a vaccum pimp and the pressure inside the tube is lowered by using this pimp and maintained to 0.01 mm. A high voltage electricity of about 10,000 V is applied between the electrodes and the result is abtained. Observation: 1)some invisible rays are emitted from the -ve cathode which makes a greenish glow at the opposite wall of discharge tube. 2)The rays coming from cathode , produces a shadow if a solid object is placed between the two electrodes; which explains that cathode rays travel in a straight line. 3)If an external electric field is applied, the cathode rays are deflected towards the +ve anode , so the rays must carry a negative charge. 4)They strike the metal foils and causes heating effect 5)They cause ionization of the gas in the discharge tbe and produce X-rays when fall over hard metals like Tungstun, Molybdenum etc. They affect the photographic plates. Conclusion: