Caused by friction when insulating materials are rubbed together:
Negatively charged electrons are scraped off one and dumped on the other,
Leaves both materials electrically charged, one has a positive static charge and a negative static charge on the other.
Which way electrons are passed depends on the two materials involved, Classic examples:
When either an acetate or polythene rod is rubbed by a cloth duster:
Polythene rod is rubbed by a cloth duster = -e move from the duster to the polythene rod.
Acetate rod is rubbed by a cloth duster…