Who determined the mass-to-charge ratio of an electron?
J.J. Thompson discovered that cathode rays were made up of
electrons, and determined the mass-to-charge ratio of the
electrons. He found that the mass-to-charge ratio of the cathode
rays was much smaller than that of hydrogen, and concluded that
constituent particles (electrons) must be the building blocks of
atoms. He modeled the neutral atom as a sphere of negatively
charged electrons distributed amongst positively charged protons.
This is known as the "plum pudding" model or the Thompson model of
Ernest Rutherford proved that the Thompson model was incorrect when he discovered that gold atoms consist of an outside layer of electrons, with a center nucleus densely packed with protons.
Millikan found the charge of an electron by his famous oil drop experiment. J J Thomson determined the specific charge of the electron. That means the ratio of the charge of an electron to its mass. With these two values one can find the mass of electron by dividing the charge value by its specific charge.
In the electron charge to mass experiment if the electron is replaced by a proton or neutron would the charge to mass ratio value still be the same why or why not?
Compared to the (charge/mass) ratio of the electron: -- The (charge/mass) ratio of the proton is much smaller; although the proton charge is equal to the electron charge, the proton mass is much larger, by a factor of more than 1,800. -- The (charge/mass) ratio of the neutron is zero, because the neutron charge is zero.
With the combined results of Thomson and Millikan, a value for the electron mass was obtained ------------------------------------ J J Thomson determined the specific charge of the electron But Millikan with his oil drop experiment determined the charge of an electron So it is easier for us to determine the mass of an electron Thanks to both scientists.