What are Canal Rays?
Positive rays are also called Canal rays.
Eugene Goldstein, in 1886, discovered positive rays in discharge tube.
Canal rays Discharge Tube Experiment:
He used a discharge tube having perforated cathode.
Goldstein noted that glow is produced on the wall opposite to anode i.e on the back of cathode. These rays were traveled towards cathode so they are positive rays. They are also called canal rays as they were passed through canals of cathode. The cathode rays when strike gas molecules, they knock out some electrons from the gas molecules thus gas cations are produce. These cations constitute canal rays.
Properties of canal rays:
- Canal rays travel in straight line
- Canal rays deflect from their straight path when passed through electric or magnetic fields.
- Canal rays are positively charged.
- Canal rays are stream of material particles which possess energy and momentum.
- They are capable of doing work.
Discovery of Proton:
Their e/m ratio depends upon nature of gas Lighter is the gas higher is e/m ratio of canal rays.
For hydrogen it is highest. Hence the positive particle obtained from hydrogen gas is lightest among all the positive particles. This particle (having e/m ratio to be 9.566 x 107 C/kg) was given the name as proton by Rutherford.