The decomposition of gaseous $H_2$ adsorbed on a metal surface like tungsten is a reaction of which order?

The charge on colloidal particles is due to

Which of the following statements is correct for physisorption?

Which statements among the following are correct?
$(i)$ Freundlich isotherm fails at high pressure of the gas.
$(ii)$ $\Delta H < 0$ for both physical and chemical adsorption.
$(iii)$ Physical adsorption is non-selective.
$(iv)$ Chemical adsorption is reversible,whereas physical adsorption is irreversible.

Which of the following is incorrect for physisorption?

Which of the following is true for the adsorption of $Krypton$ on the surface of activated charcoal at low temperature?