We explain what the liquid state is and what are the physical characteristics of this state of matter. Examples of liquids.
What is the liquid state?
A state of matter that is considered intermediate between solidity and gas is called a liquid state (or simply liquids) , since its particles are close enough to retain minimal cohesion, while dispersed enough to allow Fluency and change of form.
In any case, the particles of a liquid are halfway between the stiffness of the solid and the dispersion of the gaseous, and are usually the result of the injection of energy (fusion) in the former, or the subtraction of the same ( condensation ) in the second. Or, also, the variation of the pressure conditions of each case.
Many elements are kept in a liquid state at normal temperature, such as water itself, but when its caloric conditions are varied they can become solids (freezing or solidification, when the temperature decreases) or gases ( evaporation , when the temperature increases).
Physical characteristics of the liquid state
Matter in liquid state has the following fundamental physical characteristics:
- Shape . Liquids have no definite form, so they acquire that of the container where it is contained. A glass of water will have the shape of the glass, but a drop of water that falls will have a semi-spherical shape due to gravity .
- Flowability . It is an exclusive characteristic of liquids and gases, which allows them to leave a container in favor of another, through narrow channels or in a variable way, since the liquid particles, lacking shape, can drain, move and slide.
- Viscosity . The viscosity of liquids is their resistance to flow, due to the internal forces of their particles, whose action slows their deformation when it is poured or dropped. Thus, the most viscous liquids ( oil , pitch, etc.) flow slowly as their particles adhere more to each other; and low viscosity liquids (water, alcohol, etc.) flow rapidly.
- Adherence . Liquids can adhere to surfaces, as do the drops that remain on objects submerged in a liquid.
- Surface tension . It is a property of the surface of liquids, which resists the penetration of objects to a certain margin, as if it were an elastic layer. That is why some insects “walk” on the water and the fallen leaves of the trees remain on it without sinking. Surface tension is directly linked to density .
- Density . The particles of a liquid are held together and with cohesion thanks to their density margin, much lower than in solids, but still gives them a certain volume .
Examples of liquid state
Some examples of matter in liquid state are:
- Water . The most common substance on our planet and the universal solvent of known matter is the liquid par excellence at room temperature. There may be many dissolved substances in it, but their liquidity status is preserved. (See: Water states )
- Mercury . The only metal that remains liquid at room temperature, forming perfect, shiny and opaque silver-colored drops.
- Urine . Product of the excretory system of the human body and that of some vertebrate animals , urine is a yellowish liquid high in urea and ammonia, in which toxic wastes and metabolic wastes are expelled from the body.
- Milk . A nutritive substance that the females of the mammals secrete through the mammary glands and that consists of a whitish liquid, rich in fats and of sweet flavor.
- Gasoline . One of the most popular petroleum derivatives, it is a substance rich in hydrocarbons and extremely combustible, which makes it an input for engines and other devices that generate movement or electricity .
- Sulfuric acid . A type of acid commonly used in laboratories, which has a very high level of corrosivity and can be very harmful in contact with living organic matter.