HOW THE CATHODE RAY EXPT AND JJ THOMSON'S EXPT ARE RELATED? AS WELL AS WE KNOW THAT CATHOD RAY CONTAIN -VE CHARGED PARTICLE (NOW A DAYS KNOWN AS ELECTRON)THEN WHY WE SAY THAT JJ THOMSON' IS DISCOVER ELECTRON INSTEAD OF WILLIAM CROOKES
Dear student,
- Cathode Ray Experiment: This is also known as the discharge tube experiment because it was initially done in a discharge tube. This experiment was carried out by William Crookes in 1879 to explain the properties of negatively charged particles and the conduction of electricity through gases at low pressure.
Later, the experiment was used by J.J Thomson to explain the nature of electrons and the discovery of electrons.
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 ends, and fitted with two metal electrodes. It has a side tube fitted with a stop - cock.
Now, this tube is connected to a vacuum pump and the pressure inside the tube is lowered by using this pimp and maintained to 0.01 mm.
High voltage electricity of about 10,000 V is applied between the electrodes and the result is obtained.
Observation:
- some invisible rays are emitted from the -ve cathode which makes a greenish glow at the opposite wall of the discharge tube.
- The rays coming from the cathode produce a shadow if a solid object is placed between the two electrodes; which explains that cathode rays travel in a straight line.
- If an external electric field is applied, the cathode rays are deflected towards the +ve anode, so the rays must carry a negative charge.
- They strike the metal foils and causes a heating effect
- They cause ionization of the gas in the discharge tube and produce X-rays when falling over hard metals like Tungsten, Molybdenum, etc.
- They affect the photographic plates.
Conclusion:
- The cathode rays are made up of material particles.
- They carry a -ve charge.
Hence, the above experiment explains that cathode rays are negatively charged material particles called ELECTRONS.
Regards
- Cathode Ray Experiment: This is also known as the discharge tube experiment because it was initially done in a discharge tube. This experiment was carried out by William Crookes in 1879 to explain the properties of negatively charged particles and the conduction of electricity through gases at low pressure.
Later, the experiment was used by J.J Thomson to explain the nature of electrons and the discovery of electrons.
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 ends, and fitted with two metal electrodes. It has a side tube fitted with a stop - cock.
Now, this tube is connected to a vacuum pump and the pressure inside the tube is lowered by using this pimp and maintained to 0.01 mm.
High voltage electricity of about 10,000 V is applied between the electrodes and the result is obtained.
Observation:
- some invisible rays are emitted from the -ve cathode which makes a greenish glow at the opposite wall of the discharge tube.
- The rays coming from the cathode produce a shadow if a solid object is placed between the two electrodes; which explains that cathode rays travel in a straight line.
- If an external electric field is applied, the cathode rays are deflected towards the +ve anode, so the rays must carry a negative charge.
- They strike the metal foils and causes a heating effect
- They cause ionization of the gas in the discharge tube and produce X-rays when falling over hard metals like Tungsten, Molybdenum, etc.
- They affect the photographic plates.
Conclusion:
- The cathode rays are made up of material particles.
- They carry a -ve charge.
Hence, the above experiment explains that cathode rays are negatively charged material particles called ELECTRONS.
Regards
