Question

Which of the following is the correct electron-dot structure of `N_2O` molecule?
A. `:N=N=overset(..)underset(..)O:`
B. `:N-=overset(+)N-overset(..)underset(..)O:^(-)`
C. `:N=N=overset(..)O:`
D. `overset(..)underset(..)N=overset(..)N=overset(..)O:`

Answer 1

Correct Answer - B
The valence shell electron configuration of N and O are `2s^2 2p^3` and `2s^2 2p^4`, respectively. Thus, there are `(5xx2)+6=16`, valence electrons to account for in `N_2O`. Structure (3) is ruled out because it has 14 valence electrons while structure (4) is ruled out because it has 18 valence electrons. In structure (1), there are 16 valence electrons but the octet of terminal N is not complete. In structure (2), there are not only 16 valence electrons but the order of every atom is also satisfied.