In 1830, Michael Faraday showed that if electricity is passed through a solution of an electricity, chemical reactions occurred at the electrodes, which resulted in the liberation and deposition of matter at the electrodes.
He formulated certain laws. These results suggested the particulate nature of electricity.
An insight into the structure of atom was obtained from the experiments on electrical discharge through gases.
Before we discuss these results we need to keep a basic rule regarding the behaviour of charged particles: " Like charges repeal each other and unlike charges attached each other".
In mid 1850s many scientists mainly Faraday began to study electrical discharge in partially evacuated tubes, known as cathode ray discharge tubes.
It is depicted in picture. A cathode ray tube is made of glass containing two thin pieces of matal, called electrodes, sealed in it. The electrical discharge through the gases could be observed only at very low pressures and at very high voltages. The pressures and at very high voltage.
The pressure of different gases could be adjusted by evacuation. When sufficiently high voltage is applied across the electrodes, current starts flowing through a stream of particles moving in the tube from the native electrode (cathode) to the positive electrode (anode). These were called cathode rays or cathode ray particles.
The flow of current from cathode to anode was further checking by making a hole in the anode and coating the tube behind anode with phosphoresent meterial zinc sulphide. When these rays, after passing through anode, strike the zinc sulpide coating, a bright spot on the coating is developed (same thing happens in a telivision set).
The results of three experiments are summarised below:
1. These cathode rays star from cathode and move towards the anode.
2. These rays themselves are not visible but their behaviour can be observed with the help of certain kind of materials (fluorescent or phosphoresent) which glow when hit by them. Television picture tubes are cathode ray tubes and telivision pictures result due to fluorescence on the telivision screen coated with certain fluorescent or phosphoresent meterial.
3. In the absence of electrical or magnetic field, these rays travel in strength lines.
