Properties of the cathode rays showed that these consist of streams of negatively charged particles having very small mass. Sir J.J. Thomson called these particles as corpuscles of negative electricity. Later, G. J. Stoney called these particles as electrons.
No. Many of you while going through this article will certainly be curious to see the electron or for that matter any other sub-atomic particle. Let us illustrate with a very simple example to show how we conclude in our day-to-day life.
A school teacher had gone to Lovedale to attend a summer school workshop during the summer break after locking his apartment. One fine morning, in the early hours of the day, his neighbor had some hissing sounds which become louder and louder. The dog started barking. Something was going on in the teacher’s apartment. The neighbor became suspicious and range up the police. By the time, the police arrived; the burglars could make easy escape through the back door. The police opened the apartment and found things topsy-turvy. They found the lock of the steel almirah briken. They also found the back door open. Experts came and took the finger and foot-prints from the site.
The above history reveals that though no one had seen the burglars entering and leaving the apartment, but the number of consistent observations (like barking of the dog; hearing of the sounds by neighbor; locks found broken; back door open; missing of things; and at the top of it, the foot-prints of burglars) make us to conclude that the burglars did enter in the apartment and escaped with some precious things. Of course, from the foot-prints – their size, depth, shape and spacing etc. and other such observations, we can make out whether the burglars are males or females? What was their age? Were they having stout built? And so on.
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Similarly, were don’t see the electrons directly, but infact, we see their “foot-prints” – bursts of light on a fluorescent screen, effect on a photographic film, etc. these foot-prints confirm their existence.