In 1897, the British physicist Joseph John Thomson (1856-1940) discovered the electron after a series of experiments aimed at studying the nature of an electric discharge in vacuum. The famous scientist interpreted the deviations of the rays of electrically charged plates and magnets as evidence that electrons are much smaller than atoms.
The great physicist and scientist was to become an engineer
Thomson Joseph John, a great scientist, physicist and mentor, was supposed to be an engineer, his father thought so, but at that time the family did not have the means to pay for training. Instead, young Thomson attended college in Machester, and then in Cambridge. In 1884, he was appointed to the prestigious post of professor of experimental physics at Cambridge, although he himself conducted very few experimental works. He discovered a talent for developing equipment and diagnosing related problems. Thomson Joseph John was a good teacher, inspired his students and paid considerable attention to the broad problem of the development of the science of teaching at the university and high school.
Nobel Prize Laureate
Thomson received many different awards, including the 1906 Nobel Prize in Physics. He also had great pleasure in seeing some of his associates receive their Nobel Prizes, including Rutherford in chemistry in 1908. A number of scientists, such as William Praout and Norman Lockyer, have suggested that atoms are not the smallest particles in the universe and that they are built from more fundamental units.
Discovery of an electron (briefly)
In 1897, Thompson suggested that one of the basic units is 1000 times smaller than an atom, this subatomic particle became known as an electron. The scientist discovered this, thanks to his research on the properties of cathode rays. He estimated the mass of the cathode rays by measuring the heat generated by the heat transfer rays, and compared it with the magnetic deflection of the beam. His experiments show not only that cathode rays are 1000 times lighter than a hydrogen atom, but also that their mass was the same regardless of the type of atom. The scientist came to the conclusion that the rays consist of very light, negatively charged particles, which are a universal building material for atoms. He called these particles "corpuscles", but later scientists preferred the name "electrons", proposed by George Johnston Stoney in 1891.
Thompson's experiences
By comparing the deviation of cathode ray beams with electric and magnetic fields, the physicist obtained more reliable measurements of the charge and mass of the electron. The Thomson experiment was conducted inside special cathode ray tubes. In 1904, he hypothesized that the atomic model is a sphere of positive matter in which the position of the particles is determined by electrostatic forces. To explain the generally neutral charge of the atom, Thompson suggested that the particles were distributed in a uniform field of positive charge. The discovery of the electron made it possible to believe that the atom can be divided into even smaller parts, and was the first step towards creating a detailed model of the atom.
Discovery story
Joseph John Thomson is widely known as the discoverer of the electron. For most of his career, the professor has worked on various aspects of the conductivity of electricity through gases. In 1897 (the year the electron was discovered), he experimentally proved that the so-called cathode rays are in fact negatively charged particles in motion.
Many interesting questions are directly related to the discovery process. Obviously, the characteristics of cathode rays were dealt with even before Thomson, and several scientists have already made an important contribution. Is it possible then to say with accuracy that it was Thomson who was the first who discovered the electron? After all, he did not invent a vacuum tube or the presence of cathode rays. The discovery of an electron is a purely cumulative process. The credited discoverer makes the most important contribution, summarizing and systematizing all the experience accumulated before him.
Thomson's cathode ray tubes
The great discovery of the electron was made with the help of special equipment and under certain conditions. Thomson conducted a series of experiments using a well-thought-out cathode ray tube, which includes two plates, between them rays had to travel. Long-standing disputes regarding the nature of cathode rays arising from the passage of electric current through a vessel from which most of the air was pumped were suspended.
This vessel was a cathode ray tube. Using an advanced vacuum method, Thomson was able to put forward a convincing argument that these rays are composed of particles, regardless of the type of gas and the type of metal that was used as the conductor. Thomson can rightly be called the man who split the atom.
Scientific recluse? This is not about Thomson
The outstanding physicist of his time was by no means a scientific recluse, as is often thought of brilliant scientists. He was the administrative director of the highly successful Cavendish Laboratory. It was there that the scientist met Rose Elizabeth Paget, whom he married in 1890.
Thomson not only managed a number of research projects, he also financed the reconstruction of laboratory facilities with little support from the university and colleges. This was a talented teacher. The people he gathered around him from 1895 to 1914 came from all over the world. Some of them under his leadership received seven Nobel Prizes.
It was while working with Thomson in the Cavendish Laboratory in 1910 that
Ernest Rutherford conducted research that led to a modern understanding of the internal
structure of an atom.Thomson took his teaching activities very seriously: he regularly lectured in primary school in the morning and taught science to graduate students in the afternoon. The scientist considered the teaching useful for the researcher, because it requires periodically reviewing the basic ideas and at the same time leaving room for the possibility of discovering something new, which no one had previously paid attention to. The history of the discovery of the electron clearly confirms this. Thompson devoted most of his scientific work to the study of the passage of electrically charged current particles through rarefied gases and vacuum space. He was engaged in the study of cathode and x-rays and made a huge contribution to the study of atomic physics. In addition, Thomson also developed a theory of the motion of electrons in magnetic and electric fields.