Calculate the net charge on a substance consisting of a combination of 9.0 1013 protons and 1.0 1013 electrons.How many excess electrons are on a ball with a charge of -1.440 10-16 C?An alpha particle (charge = +2e) is sent at high speed toward a nucleus (charge = 74e). What is the electric force acting on the alpha particle when it is 2 10-14 m from this nucleus?Two electrons in an atom are separated by 1.5 10-10 m, the typical size of an atom. What is the force between them?Two negative charges of -2.9 10-6 C exert a repulsive force of 1.5 N on each other. By what distance are they separated?What is the electric force between a glass ball with 2.5 µC of charge and a rubber ball with -5.0 µC of charge when they are separated by 5 cm?Thunderstorms can have an electric field of up to 3.8 105 N/C. What is the magnitude of the electric force on an electron in such a field?An object with a net charge of 22 µC is placed in a uniform electric field of 600 N/C, directed vertically. What is the mass of this object if it floats in this electric field?