[SOLVED] Coulomb's Law 1. The problem statement, all variables and given/known data Find the magnitude of the attractive force exerted by the electrons in a cup of water on the protons in the second cup of water at a distance of 10 m. Assume that each cup contains 250g of water and that 6x10^23 water molecules (one mole) weighs 18 g. Do two cups of water exert any net force on each other? Why? 2. Relevant equations F = k*(qq/r^2) 3. The attempt at a solution 250g H2O / 18g H2O * 6.022^23 = 8.36^24 molecules of water I don't understand how to proceed after that. Do I need to find the number of electrons/protons in all H and O atoms separately and add them? Then multiply by 1.602^-19C (electron/proton charge) and plug those numbers into the formula?