The number of $3c-2e$ bond and $2c-2e$ bond present in $Be_2(CH_3)_4$ are $ . . . . . . $ and $ . . . . . . $ respectively.

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:

Which of the following compounds is polar and has a central atom with $sp^2$ hybridization?

The octet rule is not valid for which of the following molecules?

Consider the following statements:
$A$. $NF_3$ molecule has a trigonal planar structure.
$B$. Bond length of $N_2$ is shorter than $O_2$.
$C$. Isoelectronic molecules or ions have identical bond order.
$D$. Dipole moment of $H_2S$ is higher than that of water molecule.
Choose the correct answer from the options below:

The correct order of increasing bond lengths of $C-H$, $O-H$, $C-C$ and $H-H$ is