Abstract
During an experiment in 1897, J. J. Thomson discovered the existence of electrons, negatively charged subatomic particles found in the structure of atoms and responsible for various physical phenomena. Thomson also established a value for the mass to charge ratio of electrons by considering how the electromagnetic force deflects charged particles moving in a uniform magnetic field. Given the importance of electrons, this experiment seeks to confirm Thomson’s results. His process has been replicated using a vacuum tube apparatus consisting of a pair of Helmholtz coils to produce a magnetic field, a spherical evacuated tube containing helium to generate a trace of the electron path, and an electron gun in order to produce a beam of electrons. The accelerating electron voltage and the current of the Helmholtz coils were varied and the radius of the electron path was measured to derive a result of \(2.1(4) \times 10^{11} \text{C/kg}\) for the charge to mass ratio.
