Atomic Structure : Discovery of electron (CATHODE RAYS)
subscribe Discovery of electron ( CATHODE RAYS ) In 1859, Julius plucker started the study of conduction of electricity through gases at low pressure in a discharge tube. When a high voltage of the order 10,000 volts or more was impressed across the electrodes, some sort of invisible rays moved from the –ve electrode to the +ve electrode . Since the –ve electrode is referred to as cathode, these rays were called cathode rays. Properties of Cathode rays They travel in straight lines away from cathode with very high velocity . A shadow of metallic object placed in the path is cast on the wall opposite to the cathode. They produce a green glow when strick the glass wall matter. Light is emitted when they strike the zinc-sulphide screen (fluorescent material). When a small pin wheel placed in their path, the blades of the wheel are set in motion.