The decreasing order of $C-C$ bond length is:
$I.$ $C_2H_4$ $II.$ $C_2H_2$
$III.$ $C_6H_6$ $IV.$ $C_2H_6$

In which of the following options, the order of arrangement does not agree with the variation of property indicated against it?
$(a)$ $BF_3 < NF_3 < NH_3$ (Dipole moment)
$(b)$ $HgCl_2 > NH_4^+ > SF_6$ (Bond angle)

For the ozone molecule,consider the following statements:
$(A)$ It is a linear molecule with a bond angle of $180^{\circ}$.
$(B)$ It is an angular molecule with a bond angle of $117^{\circ}$.
$(C)$ The bond lengths of both $O-O$ bonds are the same.
$(D)$ With respect to oxygen,it is thermodynamically more stable.
The correct options are:

The correct order of $S-S$ bond length in the following oxyanions is:
$(I) \, S_2O_4^{2-}$
$(II) \, S_2O_5^{2-}$
$(III) \, S_2O_6^{2-}$

Which of the following statements is correct?

Which of the following is the correct decreasing order of bond length for $N_2$, $O_2$, and $Cl_2$?