Among the molecules $O_2$,$KO_2$,$H_2O_2$,$F_2O_2$ and $BaO_2$,the pair that has the most similar oxygen-oxygen bond length is:

What is the main difference between an ionic bond and a covalent bond?

Which of the following is not used as a Lewis acid?

Which of the following facts is directly explained by the statement '$O$ is a smaller atom than $S$?'

Identify the incorrectly matched set from the following:

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: