Which of the following is paramagnetic and contains a three-electron bond in its structure?

State whether the bond order increases or decreases when $O_2$ changes to $O_2^+$ and when $N_2$ changes to $N_2^+$.

Match List-$I$ with List-$II$ and select the correct option:

List-$I$ (Molecule / ion)	List-$II$ (Bond order)
$1$. $NO$	$i$. $1.5$
$2$. $CO$	$ii$. $2.0$
$3$. $O_2^{-}$	$iii$. $2.5$
$4$. $O_2$	$iv$. $3.0$

Among the following species,identify the pair having the same bond order: $CN^{-}, O_2^-, NO^{+}, CN^{+}$

Which of the following has a three-electron bond in its structure?

Fill in the blanks given below:
$(i)$ The Molecular Orbital Theory was proposed by .......... and .......... scientists.
$(ii)$ The addition of atomic orbitals results in the formation of ............ orbitals.
$(iii)$ The distribution of electrons in molecular orbitals is called .......... .
$(iv)$ The number of bonds between atoms joined by a covalent bond is called .......... .