(i) Smaller the size of the particles of adsorbent larger will be the surface area and greater will be the extent of adsorption.
(ii) At constant temperature, the extent of adsorption increases with increase of pressure, rapidly in the beginning, relatively slow at moderate Pressure and ultimately becomes independent of pressure.
(iii) At constant pressure, the physical adsorption decreases with increase of temperature whereas, the chemisorption first increases and then decreases.