Sublimation is a process in which solid directly changes into gases without going to liquid phase
It is an endothermic process ( means energy required to break the bonds of reactants is greater than the energy released when bonds are formed in products)
Sublimation occurs when the pressure of the gas is less than the vapor pressure
It occurs when relative humidity is very low and pressure is also low, so it mostly occurs at higher attitude where pressure is very low.
