Why -`NO_2` group is meta Orienting.

Explain why it is very difficult to introduce the third -NO_2 group into the benzene ring.

This question has Statement I and Statement II. Of the four choices given after the Statements, choose the one that best describes the two Statements. Statement - I : Nitration of chlorobenzene leads to the formation of ortho and para nitrochlorobenzene. Statement - II : NO_2 group is a o,p-directing group.

Name a meta-orienting group.

Which one is not meta - orienting

NO_2 is not obtained on heating -

Why are the group-2 metals harder and have higher melting and boiling points than group-I metals?

-NO_2 group …………electron density at meta-position of the ring.

Activating groups are ortho-/para-directing ,while the deactivating groups are meta-directing-why ?

Introduce the following group in benzene ring. -CH_3,-COCH_3,-CHO,-COOH,-NO_2,-NH_2,-overset(+)N_2overset(-)Cl,-CN,-Br,-C(CH_3)_3,-SO_3H