Which of the following molecules has a bond order greater than $1$?

Bond order normally gives an idea of the stability of a molecular species. All the molecules,namely $H_2$,$Li_2$,and $B_2$,have the same bond order,yet they are not equally stable. Their stability order is:

Which of the following species contain unpaired electrons: $KO_2, AlO_2^-, BaO_2$,and $NO_2^+$?

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 .......... .

If $P$ to $T$ are second period $p-$block elements,then which of the following graphs shows the correct relation between the number of valence electrons in $P_2$ to $T_2$ (corresponding molecules) and their bond order?

What is the bond order of the $O_2$ molecule?