Chapter 4.6, Problem 4.19P

${\text{NaNH}}_{\text{2}},$ sodium amid, is a salt that contains a sodium cation, ${\text{Na}}^{\text{+}}$ , and the polyatomic anion ${\text{NH}}_{\text{2}}{}^{\text{-}}$ . Draw a Lewis structure for ${\text{NH}}_{\text{2}}{}^{\text{-}}$ . Use the Lewis structure to determine which of the following ball-and-stick models represents the geometry of ${\text{NH}}_{\text{2}}{}^{\text{-}}$ .