Which process occurs in chromatography?

Adsorption of a gas on a surface follows the Freundlich adsorption isotherm. The plot of $\log \frac{x}{m}$ versus $\log P$ gives a straight line with a slope equal to $0.5$. Then,(where $\frac{x}{m}$ is the mass of the gas adsorbed per gram of adsorbent):

The equation which represents the Freundlich adsorption isotherm is ($x = \text{amount of gas}$, $m = \text{mass of solid}$):

Which of the following characteristics is not correct for physical adsorption?

The correct statement$(s)$ pertaining to the adsorption of a gas on a solid surface is (are):
$(A)$ Adsorption is always exothermic.
$(B)$ Physisorption may transform into chemisorption at high temperature.
$(C)$ Physisorption increases with increasing temperature but chemisorption decreases with increasing temperature.
$(D)$ Chemisorption is more exothermic than physisorption,however it is very slow due to higher energy of activation.

What is the number of molecular layers on the adsorbent in chemical adsorption?