Correct Answer - A::B::C
(a) and (b) are infact the same statements and both are correct. `N` has slightly greater ionisation energy than oxygen which is against periodic trend. This exception is due to completely half -filled `(2p^(3))` orbital in nitrogen that makes ionisation slightly difficult than oxygen.
(c) Also correct: Although `N` has greater first ionisation potential than oxygen, two values of ionisation potentials are comparable since they are adjacent in a period, i.e. electrons are removed from same orbit during ionisation.
(d) Incorrect- opposite to (c). of the bonded atoms which in turn has periodic trend in long form of periodic table.
