Which statement is true about a proton and an electron?
(1) they have the same masses and the same charges.
(2) they have the same masses and different charges.
(3) they have different masses and the same charges.
(4) they have different masses and different charges.

(3) They have different masses and the same charges.

Explanation:

Atoms are mainly composed of three main types of particles (in fact there are more particles that are smaller and make up these main particles): electrons, protons and neutrons.

In the specific case of  electrons and protons, both have the same charge, but electrons have the opposite sign. This means a proton has an electric charge of  +1 and an electron has an electric charge of  −1.

On the other hand, protons have more mass than electrons. In fact, thetex]mass of an electron is about approximately the mass of a proton, this means these negative charged particles contribute almost nothing to the total mass of an atom (unlike protons, which together with neutrons, make up virtually all of the mass of an atom).

However, each atom that is electrically neutral has the same quantity of electrons as protons.