Understanding Charges and connecting with Coulomb's law
Charge is what makes matter “electrically visible.”
Give an electron a charge of −e, and a proton +e. Put either one in empty space and it changes the electromagnetic field around it. Put another charge there, and that field produces a force on it.
The rule is captured by Coulomb's law:
Like charges push apart. Opposite charges pull together.
So charge isn't a tiny substance stored inside an electron.
It is a property that determines how a particle creates and responds to the electromagnetic field.
Two like charges repel — but both answer to the one opposite charge between them.
