Nitration of toluene occurs at the ....... position.

Number of $\pi$ electrons present in naphthalene is :

Which of the following species is aromatic?

In electrophilic substitution reaction,nitrobenzene is:

In the reaction of benzene with an electrophile $E^{+}$,the structure of the intermediate $\sigma$-complex can be represented as

For the electrophilic substitution reaction involving nitration,which of the following sequences regarding the rate of reaction is true?