Which of the statements given below is incorrect?

The isoelectronic pair is

What is formal charge? Explain by example.

Which of the following does not undergo Lewis acid-base reaction?

Which of the following sets are correctly matched?

Molecule	Number of lone pairs of electrons on central atom	Hybridization
$I. PCl_3$	$1$	$sp^3$
$II. SO_2$	$1$	$sp^2$
$III. SF_4$	$1$	$sp^3d$
$IV. ClF_3$	$2$	$sp^3d$

Given below are statements about some molecules/ions. Identify the $CORRECT$ statements.
$A$. The dipole moment value of $NF_3$ is higher than that of $NH_3$.
$B$. The dipole moment value of $BeH_2$ is zero.
$C$. The bond order of $O_2^{2-}$ and $F_2$ is same.
$D$. The formal charge on the central oxygen atom of ozone is $-1$.
$E$. In $NO_2$, all the three atoms satisfy the octet rule, hence it is very stable.
Choose the correct answer from the options given below: