State both the sign and the magnitude of the charge on a proton, electron, and a neutron in terms of e, the elementary charge.

-- The charge on the proton is  +1 .

-- The charge on the neutron is 0 .  No charge.

-- The charge on the electron is -1 ... same magnitude and
opposite sign compared to the charge on the proton ... even
though it takes more than 1,800 electron masses to make the
mass of one proton or one neutron.  Weird little things ! 

It's true it didin't work becouse britain continued trading with it's colonies and the system hurt economies of the countries that used it