If $N_x$ is the number of bonding orbitals of an atom and $N_y$ is the number of antibonding orbitals,then the molecule/atom will be stable if

Which of the following statements is not correct?
$I$) Bond length order: $H_2^- = H_2^+ > H_2$
$II$) $O_2^+, NO, N_2^-$ have the same bond order of $2.5$
$III$) Bond order can assume any value including zero up to four
$IV$) $NO_3^-$ and $BO_3^{3-}$ have the same bond order for the $X-O$ bond (where $X$ is the central atom)

$A$ pair of isoelectronic species having bond order of $1$ is

Pair of species among the following having same bond order as well as paramagnetic character will be -

Which of the following species contains only $\pi$-bonds but exhibits paramagnetic nature?

The pair of species that has the same bond order in the following is