For the given compounds,the correct order of resonance energy is:
$(I)$ $CH_2=CH-CH=CH-OCH_3$
$(II)$ $CH_2=CH-C(OCH_3)=CH_2$
$(III)$ $CH_2=CH-OCH_3$

Consider the following statements. Which of the following statement$(s)$ is/are correct?
$(a)$ $CH_2=CH-CH_2^+$ is more stable than $CH_3-CH^+-CH_3$.
$(b)$ Naphthalene has two types of $C-C$ bonds.
$(c)$ The structures shown are both permissible resonating structures.
$(d)$ The phenyl anion is less stable than the cyclohexadienyl anion shown.

Arrange the following in the decreasing order of stability:
$I. CH_2=CH-CHO$
$II. ^+CH_2-CH=CH-O^-$
$III. ^-CH_2-CH=CH-O^+$

Which of the following is the most unstable resonating structure?

In which of the following is the first resonating structure less stable compared to the second one?

The correct order of $C=O$ bond length in ethyl propanoate $(I)$, ethyl propenoate $(II)$ and ethenyl propanoate $(III)$ is