How does the transfer of electric forces between two objects work

[asilvester635]

Questions

1.) Here, the negative charge from the wool is transferred to the plastic rod. I'm curious as to what determines which object is responsible of transferring their charge to the other object. Like why didn't the plastic rod give its negative charge instead?

2.) If we rub 19 more neutral wools to this already negatively charged plastic rod, would that result in more transfers of negative charges from the other 19 neutral wools? Or is there a limit as to how many negative charges an object obtains?

 

[Let'sthink]

Think of what actually gets transferred when any thing gets charged as a consequence of rubbing together. Also thing what any charged body does to the atmosphere around or to the objects touching and around.

 

[sophiecentaur]

I'm curious as to what determines which object is responsible of transferring their charge to the other object.

This 'electrostatic situation' can be regarded as a bit of fringe Chemistry. Molecules are formed when electrons from one atom (or smaller molecule) are attracted to the positive charges on another atom or molecule. We learn about chemical 'Bonding" in school where this happens and results in atoms sticking together. It only works for certain combinations of elements. The details follow strict rules to do with the electrical potential energy around atoms. Some substances are electron donors when they easily give up an electron which a nearby electron acceptor can pick up. The two resulting Ions are attracted to each other and can form a compound. (That's just one form of bonding.)
When you rub two insulators together, you can mechanically dislodge some of the electrons (a very tiny proportion) from an electron donor molecule and they can be left behind on an electron acceptor molecule, giving a positively and a negatively charged surface. If the substances are good insulators, the charges on each surface will stay there and the rod / fur / etc. stays charged. This only works for situations where each of the pair can give or take an electron and when both substances are good insulators.

There is a limit to the number of times you can do this because the charges that build up on a surface will eventually repel any extra charges from being transferred.
Also, there are other ways of charging up an object (electrostatic induction) where no rubbing is involved and it works for metal objects. It's far more effective for building up high charges.

 

[Let'sthink]

Also, there are other ways of charging up an object (electrostatic induction) where no rubbing is involved and it works for metal objects. It's far more effective for building up high charges

No matter which kind of charging only one entity makes the movement or has a tendency to move. I wanted OP to guess that entity.