why do sublimates like camphor attain vapor state directly????

Answer 1

Compounds that readily sublime have a high vapor pressure at relatively low temperatures. This is usually noted in their phase diagrams.

The vapor pressure is partly the result of a more symmetrical non-polar structure than for compounds which go from the solid to liquid and then gaseous state (again at relatively low temperatures).

Almost all compounds have a triple point in their phase diagrams. At pressures below the triple point, sublimation will occur. Compounds like camphor, naphthalene, para-sublimation and caffeine have vapor pressures close to atmospheric pressures at temperatures near room temperature.

Answer 2

Sublimates

Answer 3

Some combinations sublimate directly because of their molecules shape. This could be sphere or cylinder, because these shapes dont help the formation of strong intermolecular drafts. You could also take a look at this diagram! It might help you understand that the sublimation depends from temperature and pressure. http://en.wikipedia.org/wiki/Image:Phase-diag.svg

Answer 4

Simply because of their molecular structure. The bonding is so weak that molecules enter the vapour phase at room pressure. Its only under high pressures are they obtained as liquids.