In oxygen $(O_2)$ and carbon $(C_2)$ molecules,the bonding is:

$A$ molecule which contains unpaired electrons is

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 $N_x$ 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

Consider the following statements.
$I$. In the conversion of $O_2$ to $O_2^{2+}$,bond order decreases.
$II$. In the conversion of $O_2$ to $O_2^{2+}$,magnetic property is not changed.
$III$. In the conversion of $O_2$ to $O_2^{2+}$,bond length decreases.
$IV$. $O_2^{2-}$ and $B_2$ have same bond order.
Identify the correct statements.

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