Since the electron that is lost is on the valence shell of sodium, the size of sodium will shrink while the size of chlorine will increase.
<h3>Ionic bonding</h3>
Ionic bonding is said to occur when a metal looses an electron to a nonmetal. The resulting compound is actually an ion pair.
For the formation of sodium chloride, a sodium atom looses an electron which is present on its valence shell while chlorine accepts this electrons into its valence shell as a result, the size of sodium will shrink while the size of chlorine will increase.