# What bond angles are observed in NH_4^+, OH_2, OF_2, and H_3O^+?

In $N {H}_{4}^{+}$, the $\angle H - N - H$ bond angles are $109.5$ ""^@, as we would expect for a regular tetrahedron. ${F}_{2} O$, and ${H}_{3} {O}^{+}$ share this electronic configuration, but here the central $O$ atom bears 2 and 1 lone pairs of electrons respectively. The lone pairs would tend to compress the $\angle F - O - F$ and $\angle H - O - H$ bond angles somewhat to give approx. $104 - {5}^{\circ}$.