Source 1
Speculations on the ambiguous nature and properties of the electron stretch back to the time of the ancient Greeks. The earliest interactions with this particle were through one of its properties: its electric charge. It was not until 1838, when Richard Laming proposed the first hypothesis on the concept of a unit electric charge, an atomic core, and the significance of this charge to the chemical properties of the atom it occupies [63, 64]. This electric charge was then named an electron in 1891 by George Johnstone Stoney 2. The first discovery of the electron was in 1897 by J. J. Thomson with his colleagues John S. Townsend and Harold A. Wilson; a result of an exploration of the properties of cathode rays 3. Thomson’s work suggested the relative size of the electron to that of the hydrogen atom, as well as its unchanging mass regardless of the type of atom it occupies. This discovery was monumental as it led to the development of the first model of the atom by Ernest Rutherford in Manchester (1911) 4.
An electron $(e^−)$ is thought of as a point like (dimensionless) elementary particle belonging to the first generation of the lepton family of particles. The mass of an electron is 1/1836 of the proton and is approximately $9.10938356(11) \times 10^{−31} \text{ kg}$ 5. It has an intrinsic angular momentum (spin) of 12 , and carries a negative electric charge of $−1.6021766208(98) \times 10{−19} \text{ C}$ which generates a surrounding electric field. The properties that an electron exhibits allow it to participate in a number of interactions, one of which is electromagnetic. This kind of interaction is the most relevant to the theoretical models I test and experiments I carry out.