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Matter is everything that has mass and body and occupies a place in space. It can be found in three states: liquid, solid, and gaseous. Each state has physical characteristics that characterize it.
When matter is exposed to large changes in pressure or temperature, it can experience a change in its state (from solid to gaseous, from liquid to solid, from gaseous to liquid, and vice versa). In all cases in which a change in the state of matter occurs, it does not transform into another substance but changes its physical appearance without altering its chemical composition.
The phenomena that occur when matter goes from a solid state (it has a defined shape) to a gaseous state (it does not have a defined volume or shape and expands freely), and vice versa, are:
- Sublimation. Phenomenon by which matter goes from the solid state to the gaseous state without going through the liquid state. For example: mothballs that gradually break down from solid to gaseous, dry ice (dry carbon dioxide). The substance absorbs excess energy from its environment.
- Reverse deposition or sublimation. Phenomenon by which matter goes from the gaseous state to the solid state. The gaseous particles gather more than they usually are and go directly to the solid state without going through the liquid state. This type of change is generally given by a drop in temperature and under certain pressure conditions. For example: formation of snow or frostto. This process releases energy.
However, in most cases the element goes from a gaseous state to a liquid state (condensation) and from there to a solid state. The change from gaseous to solid (and vice versa) occurs under specific conditions.
- It can help you: Physical changes
Examples from solid to gaseous (sublimation)
- Sulfur. Sublimates at high temperatures in gases with a high level of toxicity.
- Solid iodine. After sublimation it transforms into a violet colored gas.
- Arsenic. At atmospheric pressure sublimates to 613 ° C.
- Ice or snow It can sublimate at temperatures below 0 ° C.
- Benzoic acid Sublimates above 390 ° C.
- Camphor. Sublimates at a certain temperature.
- Flavoring tablet. It sublimates gradually just like naphthalene.
- More examples in: Sublimation
Examples from Gaseous to Solid (Reverse Sublimation)
- Soot. In a hot and gaseous state, it rises, comes into contact with the walls of the chimney and solidifies.
- Snow. Low temperatures cause the water vapor in the clouds to turn into snow.
- Crystals of iodine. When heated, vapors are produced, which in contact with a cold object are transformed again into iodine crystals.
