Even neutral objects can appear to be charged by having electrons move locally in their atomic positions. When a negatively charged balloon is brought near a positive wall, the electron clouds in the atoms of the wall are shifted away from the balloon. This is sufficient for the more positive side of the atoms to attract the negatively charged balloon. An electric field is a man-made construct that is used to describe what happens in space around charged objects. Much like a gravitational field has the ability to put a force on a mass, an electric field has the ability to put a force on a charge.
Electric fields exist in the vicinity of charged objects.
Due to an electric field set up by a charged wall, a 5 gram balloon charged to 1x10-7 C is suspended in air by a string as shown in the picture. Two 7 kg bowling balls are charged identically and placed in a vertical storage rack. An electron orbits a carbon nucleus at a radius of 1x10 -10 meter. Determine its velocity. Since the charges at the 20 and the 80 cm mark have the same charge and are the same distance away from the midpoint, they will cancel each other's electric field vector.