Question

The mass of an electron is

Answer 1

Remark

The electron has a mass that is roughly 1/1800 the size of either the proton or the electron. In comparison the electron's mass is very small comparred to the other 2.

Solution

A is totally wrong. A part of an atom can't weight the same as the atom.

B is totally wrong as well. See the remark above.

D is wrong. See the remark above

C is the answer. It's mass is quite small compared to the other 2.