Suppose the magnitude of the proton charge differs from the magnitude of the electron charge by a mere 1 in 10⁹.

Part A) What would be the force between two 1.2-mm-diameter copper spheres with 1.7 cm between their centers? Assume that each copper atom has an equal number of electrons and protons.

Part B) Would this amount of force be detectable? (Yes or No)

Part C) What can you conclude from the fact that no such forces are observed? (The magnitude of the proton charge differs from the magnitude of the electron charge by more/less than 1 part in 10⁹?)