D and E describe the interaction between charged objects.

What happens to the air between two charged objects to allow a spark to jump between them?

So the gold leaves remain separated even after the nearby charged object is moved away.

This model produces its own field, so there's no need to insert a charged object.

The difference is in the imaginary sphere which encloses this charged object.

Double layer forces occur between charged objects across liquids, typically water.

A charged object outside any container also induces an equal charge on its surroundings.

If several charged objects are lowered into the container, the charge on the outside will be equal to their sum.

There is a charged object in empty space, Q+.

He also noted that two charged objects repelled each other.