The paramagnetic nature of oxygen molecule is best explained on the basis of

The total number of anti bonding molecular orbitals, formed from $2 \mathrm{~s}$ and $2 \mathrm{p}$ atomic orbitals in a diatomic molecule is_______

When $O _2$ is adsorbed on a metallic surface, electron transfer occurs from the metal to $O _2$. The $TRUE$ statement$(s)$ regarding this adsorption is(are)

$(A)$ $O _2$ is physisorbed

$(B)$ heat is released

$(C)$ occupancy of $\pi_{2 p }^*$ of $O _2$ is increased

$(D)$ bond length of $O _2$ is increased

Assuming that Hund's rule is violated, the bond order and magnetic nature of the diatomic molecule $B_2$ is

The bond order and magnetic property of acetylide ion are same as that of $........$.

Which of the following molecular orbitals has maximum number of nodal planes ?