The smell of hot sizzling food reaches us several metres away. However, it is not so in case the food is cold. Explain.
When food is sizzling hot, it releases the vapours of its contents. Since the kinetic energy of the particles is very high in the vapour state, these particles readily mix up with the particles of air. They can reach us even at a distance of several metres. However, when the food is cold, the vapours released will be comparatively less. Moreover, their kinetic energy is also very small. Under these conditions, one has to come quite close in order to smell the contents of the food.