Which multiple bonds are present in $CO_{2}$,$C_{2}H_{4}$,$N_{2}$,and $C_{2}H_{2}$? Draw the Lewis and simple bond structures of these molecules.

(N/A) Carbon dioxide $(CO_{2})$: In the $CO_{2}$ molecule,two double bonds are present. Each $C=O$ bond involves two electron pairs (four electrons) shared between $C$ and $O$ atoms.
$(b)$ Ethene $(C_{2}H_{4})$: In this molecule,one double bond $(C=C)$ is present between two carbon atoms,and four single $C-H$ bonds are present. Between the two carbon atoms,two electron pairs (four electrons) are shared,forming a double bond.
$(c)$ Dinitrogen $(N_{2})$: In the $N_{2}$ molecule,a triple bond $(N \equiv N)$ is present between the two nitrogen atoms,involving three electron pairs (six electrons).
$(d)$ Ethyne $(C_{2}H_{2})$: In this molecule,one triple bond $(C \equiv C)$ is present between two carbon atoms,and two single $C-H$ bonds are present. Between the two carbon atoms,three electron pairs (six electrons) are shared,forming a triple bond.