Which of the following molecules has unequal bond lengths?

Choose the correct statement:

In which of the following pairs,both the species have the same hybridisation?
$I$. $SF_4, XeF_4$
$II$. $I_3^-, XeF_2$
$III$. $ICl_4^+, SiCl_4$
$IV$. $ClO_3^-, PO_4^{3-}$

What is the hybridisation state of the central atom and the shape of the conjugate base of the ammonium ion?

What is meant by hybridisation of atomic orbitals? Describe the shapes of $sp$,$sp^{2}$,$sp^{3}$ hybrid orbitals.

What is the type of hybridization in $ICl_7$?