According to molecular orbital theory, the species among the following that does not exist is :

The correct set from the following in which both pairs are in correct order of melting point is :

The correct shape and $$I - I - I$$ bond angles respectively in $$I_3^ - $$ ion are :

Which of the following are isostructural pairs ?

A. $$SO_4^{2 - }$$ and $$CrO_4^{2 - }$$

B. SiCl₄, and TiCl₄

C. NH₃ and NO₃^-

D. BCl₃ and BrCl₃