(1) $CH_2=CH_2$
(2) $[Figure]$
(3) $H-C \equiv C-H$
(4) $NH_3$
$\begin{matrix}
\overset{\Theta }{\mathop{\overset{\centerdot \,\centerdot }{\mathop{C}}\,}}\,{{H}_{2}}-C-C{{H}_{3}} \\
|| \\
O \\
\end{matrix}$ અને $\begin{matrix}
C{{H}_{2}}=C-C{{H}_{3}} \\
| \\
:\underset{\Theta }{\mathop{\underset{\centerdot \,\centerdot }{\mathop{O}}\,}}\,: \\
\end{matrix}$
$(i)$ $\begin{array}{*{20}{c}}
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,C{H_3}} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|} \\
{C{H_3} - {C^ \mathbf{-} }} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,C{H_3}}
\end{array}$
$(ii)\;\;CH_2 = CH -\stackrel{\mathbf{-}}{C}H_2$
$(iii)\;\;CH \equiv \stackrel{\mathbf{-}}{C}$
$(iv)\;\;\stackrel{\mathbf{-}}{C}H_3$
$(v)\;\;\stackrel{\mathbf{-}}{C}N$