Protons, like electrons, are charged 1.6x10^-19 Coulombs
The +- sign in the picture represents the indivisible smallest unit of positive and negative electromagnetic information - quantum bit (qubit)
p>(The famous physicist John Wheeler once said: All things come from bits.
After the rise of quantum information research, this concept was sublimated to: All things come from quantum. Bits)
Note: Bits are bits