Answer: Friction.
Explanation:
Friction is the act of charging an object by contant via rubbing (with another substance)
A low electron composed substance will be rubbed against another substance with a high electron composition. When this happens, the amount of electrons in the low composition substance will decrease, and eventually the substance gains a positive charge.
During the same process, the high composition electron substance will gain more electrons and switches its charge, to negative, of course.
Because of this, there's a transfer of the elctrons that exchange from one substance to another in the process.
