Sodium chloride (NaCl) is an ionic compound. We can effectively model it as sodium atoms with one electron removed next to chlorine atoms with one electron added. The attractive force between the positive and negative charges holds the crystal together. If we model the sodium and chlorine ions as point charges separated by 0.28 nm, the spacing in the crystal, what is the magnitude of the attractive force between two adjacent ions? How does this force compare to the weight of the sodium ion, which has a mass of 23 u?