b
(b) The electronic configuration of nitrogen is \(_7N = 1{s^2},2{s^2},2{p^3}\) It has \(5\) electrons in valency shell, hence in ammonia molecule it complete its octet by sharing of three electron with three \(H\) atom, therefore it has \(8\) electrons in its valence shell in ammonia molecule

\(\mathop {\mathop {H \times \cdot \mathop N\limits_.^{.\;.} \cdot \; \times H}\limits_ \times }\limits_H \) or \(\mathop {H - \mathop N\limits_|^{.\;.} - H}\limits_{\,H} \)