VaVi  Sports equipment sublimated
Sublimation is the process of transformation  
directly from the solid phase to the gas phase  
without passing through an intermediate liquid  
phase. Sublimation is an exothermic phase  
transition that occurs at temperatures and  
pressures below a substance's triple point in its  
phase diagram.

At normal pressures, most chemical compounds and elements possess three different states at different  
temperatures. In these cases, the transition from the solid to the gaseous state requires an intermediate  
liquid state. Note, however, that the pressure referred to here is the partial pressure of the substance, not the  
total (e.g., atmospheric) pressure of the entire system. So, all solids that possess an appreciable vapor  
pressure at a certain temperature usually can sublime in air (e.g., water ice just below 0C). For some  
substances, such as carbon and arsenical, sublimation is much easier than evaporation from the melt,  
because the pressure of their triple point is very high, and it is difficult to obtain them as liquids.
Sublimation requires additional energy and is an endothermic change. The enthalpy of sublimation (also  
called heat of sublimation) can be calculated as the enthalpy of fusion plus the enthalpy of vaporization. The  
reverse process of sublimation is deposition. The formation of frost is an example of meteorological  
(C)  2012 - VaVi  Sports equipment sublimated