Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state. At normal pressures, most chemical compounds and elements possess three different states at different temperatures. The term sublimation refers to a physical change of state and is not used to describe the transformation sublimation valentine gifts a solid to a gas in a chemical reaction.

For example, the dissociation on heating of solid ammonium chloride into hydrogen chloride and ammonia is not sublimation but a chemical reaction. Sublimation is caused by the absorption of heat which provides enough energy for some molecules to overcome the attractive forces of their neighbors and escape into the vapor phase. Since the process requires additional energy, it is an endothermic change. As dry ice is heated, it crosses this point along the bold horizontal line from the solid phase directly into the gaseous phase. Water, on the other hand, passes through a liquid phase at 1 atmosphere.

Naphthalene, an organic compound commonly found in pesticides such as mothballs, sublimes easily because it is made of non-polar molecules that are held together only by van der Waals intermolecular forces. C, to make the solid form of naphthalene evaporate into gas. On cool surfaces, the naphthalene vapours will solidify to form needle-like crystals. Solid compound of naphthalene sublimed to form a crystal-like structure on the cool surface. Camphor subliming in a cold finger. Iodine produces fumes on gentle heating, although this is above the triple point and therefore not true sublimation. It is possible to obtain liquid iodine at atmospheric pressure by controlling the temperature at just above the melting point of iodine.

In forensic science, iodine vapor can reveal latent fingerprints on paper. Cadmium and zinc are not suitable materials for use in vacuum because they sublime much more than other common materials. Sublimation is a technique used by chemists to purify compounds. A solid is typically placed in a sublimation apparatus and heated under vacuum. In ancient alchemy, a protoscience that contributed to the development of modern chemistry and medicine, alchemists developed a structure of basic laboratory techniques, theory, terminology, and experimental methods. The first cause is to make the body spiritual.