$9.$ An electron $($with charge $-1\mathrm{.}602*10^-19*$ C $)$ and an oxygen nucleus $($with mass $2\mathrm{.}6552*10^-26|$ and charge $1\mathrm{.}282$ x $10-18$ C$)$ are separated by a distance of $6\mathrm{.}5*10^-11*$m