is there any studies on : an electron is exactly equal to another electron in mass and charge ?

Question

or .. the same question for protons and neutons ..

Answer 1

The mass of the electron has been measured to an accuracy of 0.17 parts per million. That's consistent with all electrons having the same mass, but not enough to rule out the possibility of more than one mass value where all are within the accuracy limits of our measurements. The proton mass is known to the same accuracy.

The charge of the electron has been measured to 85 parts per billion. No measurement has found a difference in magnitude between the electron and proton charge.

To answer the question, I would try to think of experiments whose outcome would be different if the mass or charge differed. I would also run lots of simulations with varying assumptions for those values. Quantum effects make it extremely difficult to measure the results of such experiments.

Answer 2

Have you not ever done Milikin's oildrop experiment? It is a very fameous experiment to determine the charge on an electron. As far as mass of electrons is concerned, the now old-fashioned "picture tube" or cathode ray tube relied on the fact that every electron has the same mass (and the same charge, for that matter).

Answer 3

In charge surely for the absolute value since we know negative (in the matter) and positive (artificial electrons)

For the mass. At rest they have the same mass. But you know that they move at a great speed and Einstein showed that the mass vary with the speed. So electrons with great different speeds can see their mass vary

Answer 4

actually it is difficult to predict the mass of an electron... so what exacytly calculated is the ratio of the charge on an electron to the mass of an electron...