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

Of the species, $NO , NO ^{+}, NO ^{2+}, NO ^{-},$ the one with minimum bond strength is :

Which is set of paramagnetic molecules or ions

The paramagnetic property of the oxygen molecule due to the presence of unpaired electorns present in

For diatomic molecules, the correct statement($s$) about the molecular orbitals formed by the overlap to two $2 p_z$ orbitals is(are)

$(A)$ $\sigma$ orbital has a total of two nodal planes.

$(B)$ $\sigma^*$ orbital has one node in the $x z$-plane containing the molecular axis.

$(C)$ $\pi$ orbital has one node in the plane which is perpendicular to the molecular axis and goes through the center of the molecule.

$(D)$ $\pi^*$ orbital has one node in the $x y$-plane containing the molecular axis.

Which of the following facts given is not correct ?
$(I)$ Bond length order : $H^-_2 = H^+_2 > H_2$

$(II)\, O^+_2 ,NO,N^-_2$ have same bond order of $2 \frac{1}{2}$

$(III)$ Bond order can assume any value including zero upto four

$(IV)\, NO^-_3$ and $BO^-_3$ have same bond order for $X - O$ bond (where $X$ is central atom)