How have studies of electrons and the atomic structure started?

About unknown energy emitted by cathodes and radium…

In the discovery of electrons, a prominent role has been played by so-called cathode rays. Initially, to explain this phenomenon, the wave hypothesis was put forward: cathode rays would be a process in aether. The English physicist William Crookes has expressed the idea that cathode rays is a stream of tiny particles of material. In 1895, the French physicist Jean Perrin has experimentally proved that it is a stream of negatively charged particles moving in a straight line, which (i) can be deflected by magnetic fields, (ii) possess kinetic energy and are capable of transmitting mechanical motion to a turntable with blades. In the same year, J. J. Thomson has shown that all the particles forming cathode rays are identical and are part of substance. Meanwhile, Pierre Curie has discovered that magnetic field deflects the radiation of radium, which is called beta rays. Further experiments have shown there is no fundamental difference between beta and cathode rays. The hypothesis of the existence of matter in a state of even more fine-granular than atoms was outlined by Thomson in 1897, after finding the charge to mass ratio of the cathode-ray particles does not depend on the material of their source.

The first man-made source of electrons  --  cathode-ray tube

A cathode tube emits rays with properties similar to those of radioactive-radium rays.


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