All bonds in benzene are equal due to

Which of the following resonance structures is more stable? Explain your answer.

The $S-O$ and $P-O$ bond order in $SO_4^{2-}$ and $PO_4^{3-}$ are respectively:

Draw the resonance structures for the following compounds. Show the electron shift using curved-arrow notation.
$(a)$ $C_{6}H_{5}OH$
$(b)$ $C_{6}H_{5}NO_{2}$
$(c)$ $CH_{3}CH=CH-CHO$
$(d)$ $C_{6}H_{5}CHO$
$(e)$ $C_{6}H_{5}CH_{2}^{+}$
$(f)$ $CH_{3}CH=CH-CH_{2}^{+}$

Among the following,the least stable resonance structure is

Which of the following compounds does not exhibit the resonance effect?