The nature of cathode rays depends on the nature of gas taken in the discharge tube.
In 1897, J. J. Thomson determined the e/m value (charge/mass) of the electron by studying the deflections of cathode rays in electric and magnetic fields. The value of e / m has been found to be
By performing a series of experiments, Thomson proved that whatever the gas taken in the discharge tube and whatever the material of the electrodes, the value of e / m is always the same. Electrons are thus common universal constituents of all atoms.
Hence, the given statement is false.