April 30, 1897 - Joseph J. Thomson discovered the electron

He was a British scientist who found many achievements in his scientific career:

• He performed a series of experiments on cathode ray tubes that led to the discovery of electrons.
• He invented positive lightning and discovered how to use it to separate atoms of different masses by deflecting them using electric and magnetic fields (mass spectrometry). Thus he discovered that neon has two isotopes (Ne-20 and Ne-22).
• He showed that hydrogen has a single electron, allowing him to confirm or reject various theories that existed up to now about the number of electrons, just like carbon.
• He proposed a second atomic model (the first was proposed by John Dalton in 1794), which could be characterized as a positively charged sphere in which electrons are embedded.

In 1906, he was awarded the Nobel Prize in Physics in recognition of the great merits of his theoretical and experimental research on the conduction of electricity generated by gases.

In 1991, the Thomson (Th) = 1.036 x 10-8 KgC-1 was proposed by chemists as a mass-charge unit of measure in mass spectroscopy. However, it has become an obsolete unit and has not been incorporated into the International System.

As a curiosity, he had a son, George Paget Thomson who became a prominent physicist, who in turn was awarded the Nobel Prize in Physics in 1937 for demonstrating the wave-like properties of electrons.

If you want to know more about this scientist, click on the following link: Joseph J. Thomson