discovery of cathode rays

The discovery of cathode rays led to a vast field of practical application in Electronics. The glow produced by the fast moving electrons on a fluorescent screen led to its use in radar and television. The oscilloscope has many points in common with the discharge tube..

When the pressure in the discharge tube is less than 10 - 4 mm of Hg, the discharge tube starts showing fluorescence. When this fluorescence was investigated, it was found that the fluorescence consisted of beams of negatively charged electrons. These electrons emanate normally from the cathod..

Cathode rays travel in straight lines from the cathode to anode and cast shadow of the object placed in their path. (a) Cathode rays travel in straight lines. Cathode rays consist of an invisible stream of negatively cha..

In 1885, Sir William Crookes carried out a series of investigations into the behaviour of metals heated in a vacuum. The experiment of Crookes and others showed that a heated cathode produced a stream of radiation, which could cause gases at low pressure to glow and which made other subs..

Modern Physics..

Travel in Straight LinesWhen an opaque object like a metal cross is placed in the path of cathode rays in a discharge tube, a shadow of the metal cross is formed at the end opposite to the cathode. The placement of the shadow proved that these rays follow a..

Production of cathode rays - In 1885, Sir William Crookes carried out a series of investigations into the behaviour of metals heated in a vacuum. The experiment of Crookes and others showed that a heated cathode produced a stream of radiation, which could cause gases a..

Electron - Discharge Tube experiments - These experiments were conducted in detail by J.J. Thomson and he studied the passage of electricity through gases at extremely low pressure in a cylindrical glass tube. It was discovered that at extremely low pressure, gases become conductors of electricity ..

Production of anode rays - Since the atom is electrically neutral there must be positively charged particles present in the atom to neutralize the negative charges of the electrons. Goldstein experimentally proved the existence of protons in the ato..

The whole mass of an atom is due to the nucleus, which means that the nucleus must contain protons equal to the mass of the atom. As the number of protons is equal to the atomic number, the atomic mass should be equal to the atomic number. But for all atoms except hydrogen the atomic mass is found..