$A$ plot of $\log \left( \frac{x}{m} \right)$ vs $\log \, P$ for the adsorption of a gas on a solid gives a straight line with slope equal to

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 $\pi_{2p}^{*}$ of $O_{2}$ is increased
$(D)$ bond length of $O_{2}$ is increased

Which one of the following statements is not correct?

The correct statement regarding chemisorption is

The charcoal maintained at $100 \ K$ absorbs

Correct for physical adsorption is