In the notes, if something is underlined, you can click it. If we bring two dissimilar atoms together, an electron may be transfered from one to the other. The two atoms stick. Like gravity, the electric force is a vector along the line connecting the charges and varies inversely with the square of distance. Charge plays the role of mass.
G is replaced with k and specifies the strength.
Forces from multiple charges add as vectors. The charged particles in condensed matter are bound by electrical forces. Dissolved charged ions may move in a liquid. These materials are conductors of electric charge. Excess electrons in a conductor repel and distribute around the surface, where a potential barrier prevents escape, in such a way that the total electric force vanishes in the interior.