SECTION $22\mathrm{.}3$ Coulomb's Law

$2.($a$)$ Find the magnitude of the electric force between a $N{a}^{+}$ Q$1$C ion and a $C{l}^{-}$ion separated by $0\mathrm{.}50$ nm $.($b$)$ Would the answer change if the sodium ion were replaced by $L{i}^{+}$and the chloride ion by $B{r}^{-}?$ Explain.

$3.$ In a thundercloud, there may be electric charges of $+40\mathrm{.}0$ C near the top of the cloud and $-40\mathrm{.}0$ C near the bottom of