In gaseous triethylamine,the $C-N-C$ bond angle is $.....$ degrees.

In which of the following conversions does a planar compound change into a non-planar compound?
$(a)$ $ClF_3 \rightarrow ClF_4^{-}$
$(b)$ $NH_2^{-} \rightarrow NH_4^{+}$
$(c)$ $I_3^{+} \rightarrow I_3^{-}$
$(d)$ $SO_2 \rightarrow SO_3$

Consider the species $CH_4$,$NH_4^+$ and $BH_4^-$. Choose the correct option with respect to these species.

Which of the following has the least bond angle?

The correct statement regarding the number of lone pairs on the central atoms of the molecules $SF_4$,$CF_4$,and $XeF_4$ is:

Carbon suboxide $C_3O_2$ has