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- El líquid és un dels estats de la matèria més quotidians. És un fluid, dins del qual els àtoms o molècules que el formen es mouen lliurement en el seu interior. A diferència dels gasos (també fluids), les distàncies entre les seves molècules són casi invariants pel que se'ls considera pràcticament incompressibles. En canvi, la matèria en estat líquid és fàcilment deformable. La superfície és una superfície lliure en què el líquid no està limitat per un contenidor. El pas de l'estat sòlid a l'estat líquid es coneix com a fusió, i el pas invers és la solidificació (conegut com a congelació quan es deu a una reducció de la temperatura). El pas de l'estat líquid a l'estat gasós es coneix com a vaporització, i el pas invers és la condensació. Els líquids es mesuren en unitats de volum, la del Sistema Internacional és el litre. Alguns exemples de líquids ingerits pels homes són l'aigua, la llet o el vi.
- Kapalina neboli kapalná látka je jedno ze skupenství látek, při kterém jsou částice látky relativně blízko sebe, ale nejsou vázány v pevných polohách a mohou se pohybovat v celém objemu. Kinetická energie částic kapaliny je malá ve srovnání s vazební potenciální energií, takže částice se vzájemně udržují v určitých rovnovážných polohách, kolem kterých vykonávají kmitavý pohyb. Tyto rovnovážné polohy se u kapalin mohou přemisťovat, tzn. dochází k přemísťování částic v celém objemu látky. Vazba mezi částicemi zajišťuje, že za běžných podmínek se objem látky nemění. Kapalina bývá také považována za přechodnou fázi mezi pevnou látkou a plynem.
- Eine Flüssigkeit ist Materie im flüssigen Aggregatzustand. Nach einer makroskopischen Definition handelt es sich um einen Stoff, der einer Formänderung so gut wie keinen, einer Volumenänderung hingegen einen recht großen Widerstand entgegensetzt (der Stoff ist nahezu inkompressibel). Nach einer mikroskopischen Definition ist eine Flüssigkeit ein Stoff, dessen Teilchen sich ständig nichtperiodisch bewegen sowie keinerlei Fernordnung, jedoch sehr wohl einer Nahordnung unterliegen und deren mittlere freie Weglänge in der Größenordnung des Teilchendurchmessers liegt. Flüssigkeiten sind also volumenbeständig, formunbeständig und unterliegen einer ständigen Brownschen Bewegung. Der flüssige Zustand ist nicht allein stoffspezifisch, sondern hängt auch von äußeren Faktoren wie der Temperatur und dem Druck ab. Wechselt eine solche Flüssigkeit ihren Aggregatzustand, so spricht man von einer Phasenumwandlung, wobei der Begriff der Phase selbst einen Überbegriff zum Aggregatzustand darstellt. Mit den Gasen werden die Flüssigkeiten zu den Fluiden zusammengefasst.
- El líquido es un estado de agregación de la materia en forma de fluido altamente incompresible (lo que significa que su volumen es, muy aproximadamente, constante en un rango grande de presión).
- Neste on yksi aineen olomuodoista. Sulamispisteessä kiinteä aine sulaa ja muuttuu nesteeksi. Nesteessä rakenneosat siirtyilevät, mutta niiden väliset vuorovaikutukset ovat voimakkaampia kuin kaasufaasissa. Aine on nesteenä, kun se on kiehumis- ja sulamispisteiden välissä. Neste on usein pisaroissa tai lammikoissa pintajännityksen vuoksi. Viskositeetti kuvaa nesteen sisäisen virtauksen vastustuksen voimakkuuden. Ns. täydellinen neste tarkoittaa nestettä, jossa ei ole lainkaan kitkaa. Käytännössä tämä tarkoittaisi esim. sitä, että teelusikalla hämmennetty neste teekupissa jatkaisi liikettään ikuisesti tasaantumatta.
- La phase liquide est un état de la matière. Sous cette forme, la matière est facilement déformable mais difficilement compressible. Le liquide est une forme de fluide : les molécules sont faiblement liées, ce qui rend les liquides parfaitement déformables. Mais, à l'inverse du gaz, elles sont tout de même liées : une molécule ne peut s'éloigner beaucoup d'une autre, ce qui fait que la matière liquide a une cohésion que ne possède pas le gaz (et comme dans les solides, les molécules sont très proches les unes des autres, ce qui rend les liquides difficilement compressibles).
- A folyadék (ideális folyadéknak tekintve) az anyagnak azon halmazállapota, amelyben az anyag felveszi a tárolásra szolgáló edény alakját, megtartja a térfogatát és nem képes csavaróerők továbbítására. Gyakorlatilag összenyomhatatlan, részecskéi állandóan, tetszőleges módon helyet változtatnak. A részecskék – sok szilárd anyagtól eltérően – rendezetlenül helyezkednek el, eltekintve egyfajta enyhe fokú, laza rendezettségtől.
- Il liquido è uno degli stati della materia.
- 液体（えきたい）は物質の三態の一つである。気体と同様に流動的で、容器に合わせて形を変える。液体は気体に比して圧縮性が小さい。気体とは異なり、容器全体に広がることはなく、ほぼ一定の密度を保つ。液体特有の性質として表面張力があり、それによって「濡れ」という現象が起きる。 液体の密度は一般に固体のそれに近く、気体よりもはるかに高い密度を持つ。そこで液体と固体をまとめて「凝集系」などとも呼ぶ。一方で液体と気体は流動性を共有しているため、それらをあわせて流体と呼ぶ。
- 액체(液體)는 간단히 말해 물질의 상으로 물처럼 부피는 일정하지만 자유롭게 모양을 바꿀 수 있는 유체를 말한다. 구체적으로 말해 액체는 50℃에서 300kPa(3bar) 이하의 증기압을 가지고, 20℃ 및 101.3kPa에서 완전히 가스상이 아니며 또한 101.3kPa에서 녹는점 또는 초기 녹는점이 20℃ 이하인 물질을 말한다. 끓는점 이상의 온도에서 기체로, 어는점 이하에서 고체로 상을 바꾼다. 액체는 고체와 달리 어떤 모양의 그릇에나 들어갈 수가 있다. 이것은 액체를 이루고 있는 입자가 고체의 경우보다 상호간의 결합력이 약하여 움직이기 쉽기 때문이다. 또, 기체를 주사기에 넣고 구멍을 막은 다음 피스톤을 밀었다가 뺐다가 하면 기체의 부피가 변한다. 그러나 액체는 이와 같이 해도 부피가 변하지 않는다. 이것은 액체를 이루고 있는 입자의 틈새가 기체의 경우보다 훨씬 작기 때문이다.
- Vloeistof is een van de aggregatietoestanden waarin stoffen kunnen voorkomen. In deze toestand is de stof vloeibaar, in de scheikunde ook wel afgekort met l (liquid). Afhankelijk van de temperatuur verandert de viscositeit van de stof van stroperig tot dun vloeibaar. Ook kan de stof bij zeer lage temperatuur supervloeibaar worden. Door de oppervlaktespanning van een vloeistof te verlagen kan deze zeer dun uitlopen en luchtbellen vormen. Een vloeistof in een smalle buis kan afhankelijk van de soort vloeistof en het buismateriaal adhesie of cohesie vertonen. Vloeistoffen worden op veel gebieden toegepast, als: smeermiddel, zoals olie bakmiddel, zoals plantaardige olie krachtoverbrengmiddel in hogedrukleidingen, zoals hydraulische olie bij een tractor of in een remleiding van een auto transportmiddel, zoals water bij sleephopperzuigers oplosmiddel, zoals wasbenzine Wij kennen slechts een beperkt aantal zuivere stoffen in de eerste plaats (dat wil zeggen bij kamertemperatuur onder druk van één atmosfeer) als vloeistof. Hieronder vallen water, alcohol, aceton, kwik, koolstofdisulfide, benzeen en een aantal alkanen van pentaan af tot en met hexadecaan. Een enkele stof met hoge viscositeit blijkt zich toch onverwacht als een vloeistof te gedragen, zoals asfalt of bitumen, aangetoond door het pekdruppelexperiment. Verder gedragen veel kunststoffen zich op grote tijdschaal als een vloeistof; een extreem voorbeeld daarvan is Silly Putty.
- Væske betegner en aggregattilstand (fase) som har fast volum men ikke fast form. I likhet med gasser, kan væsker flyte (strømme) og endre form på vilkårlig måte, men vil i motsetning til gasser ikke fylle tilgjengelig volum i en beholder. Faststoff har tilnærmet fast volum, men kan i motsetning til væske ikke endre form på vilkårlig måte. Væsker kan flyte mer eller mindre lett, hvor vann er et eksempel på en væske som flyter lett, mens honning er seigtflytende. Væske er, sammen med faststoff og gass, en av de tre klassiske aggregattilstandene og et svært viktig begrep i fysikk, kjemi og andre naturvitenskaper.
- Ciecz – stan skupienia materii – pośredni między ciałem stałym a gazem, w którym ciało fizyczne trudno zmienia objętość, a łatwo zmienia kształt. Wskutek tego ciecz przyjmuje kształt naczynia, w którym się znajduje, ale w przeciwieństwie do gazu nie rozszerza się, aby wypełnić je całe. Powierzchnia styku cieczy z gazem lub próżnią nazywa się powierzchnią swobodną cieczy. Istnienie cieczy ogranicza od strony niskich temperatur temperatura krzepnięcia, a od wysokich temperatura wrzenia. Czysta ciecz może istnieć w temperaturze niższej od temperatury krzepnięcia – nazywana jest wówczas cieczą przechłodzoną. Może ona także istnieć w temperaturze wyższej od temperatury wrzenia – jest wtedy nazywana cieczą przegrzaną. Ciecz przechłodzona lub przegrzana jest w nietrwałym stanie termodynamicznym i pod wpływem zanieczyszczenia lub zaburzenia odpowiednio krzepnie lub wrze. Niektóre substancje ciekłe o dużej lepkości nie krystalizują się, pozostając w stanie amorficznym, który formalnie biorąc jest cieczą przechłodzoną. Własności cieczy wynikają z zachowania się jej cząsteczek: podobnie jak w gazie, mają one pełną swobodę przemieszczania się w objętości zajmowanej przez ciecz występują między nimi oddziaływania międzycząsteczkowe, które się jednak w obrębie objętości cieczy znoszą nawzajem. oddziaływania międzycząsteczkowe nie znoszą się na granicy cieczy z inną fazą na skutek czego występuje zjawisko zwane napięciem powierzchniowym.
- O estado líquido é um estado da matéria no qual a distância entre suas moléculas é suficiente para se adequar a qualquer meio (tomando sua forma), porém sem alterar o volume. Um líquido é uma das cinco principais fases da matéria. E dito um fluido aquilo cuja a forma é usualmente determinada por aquilo que o contem. As partículas do líquido (normalmente moléculas ou conjunto de moléculas) estão livres para se mover por todo o volume do líquido, mas sua atração mútua limita a capacidade destas partículas abandonarem o volume. O volume de uma quantidade de um liquido é determinado pela sua pressão e temperatura. Se este volume difere ligeiramente do volume do recipiente que o contem, uma superfície é observada. A superfície do liquido se comporta como uma membrana elástica, na qual a tensão superficial se manifesta. Devido a este efeito, o liquido forma gotas e bolhas. A Capilaridade é outra consequência da tensão superficial. O Líquido exerce pressão nos lados de um recipiente como também em qualquer coisa nela imersa. Esta pressão é transmitida em todas as direções e aumenta com a profundidade. Se um líquido está submetido a um campo gravitacional uniforme. A pressão a um dado ponto é dada por : onde: = a densidade do líquido (assumida constante) = gravidade = a distância do ponto em relação a superfície. Note que esta formula assume que a pressão na superfície livre do líquido é zero, e que os efeitos da tensão superficial podem ser negligenciados. Líquidos geralmente expandem quando são aquecidos, e contraem quando esfriados. Objetos imersos em líquidos são submetidos para o fenômeno do empuxo. Líquidos ao seu respectivo ponto de ebulição convertem-se para gás, e ao seu ponto de congelamento, transformam-se em sólido. Mesmo abaixo do ponto de ebulição o líquido evapora na superfície. Um líquido irá evaporar até que a concentração de vapor que o cerca alcançar uma pressão parcial de equilíbrio. Portanto nenhum líquido pode existir permanentemente no vácuo. Via destilação fracionada, os componentes líquidos de uma mistura podem ser separados, utilizando-se do fato de possuírem pontos de ebulição distintos. Vidro a temperatura normal pode ser considerado um "líquido super-resfriado" ou um sólido, dependendo do ponto de vista. Veja o artigo vidro para maiores detalhes.
- Жи́дкость — одно из агрегатных состояний вещества. Основным свойством жидкости, отличающим её от других агрегатных состояний, является способность неограниченно менять форму под действием касательных механических напряжений, даже сколь угодно малых, практически сохраняя при этом объём.
- Vätska eller flytande form är ett aggregationstillstånd för kondenserad materia, som kännetecknas av att tillståndet inte har elastisk deformation vid skjuvning. Vanliga vätskor har låg viskositet så att en vätska i en bägare snabbt får samma form som bägaren. Symbolen (l) används för att ange att ett ämne är i flytande form. Symbolen sätts tätt intill, i samma teckengrad och i rak stil, det ämne eller den förening den tillhör: H2O(l) betecknar flytande vatten.
- Рідина́ — один з основних агрегатних станів речовини поряд із газом та твердим тілом. Від газу рідина відрізняється тим, що зберігає свій об'єм, а від твердого тіла тим, що не зберігає форму. Рух рідин та тіл в рідинах вивчає розділ фізики гідродинаміка, будову та фізичні властивості рідин — фізика рідин, складова частнина молекулярної фізики.
- Chất lỏng là một trạng thái vật chất khá phổ biến. Chất lỏng là một chất lưu mà các phân tử cấu tạo nên nó có liên kết không chặt so với liên kết rắn và có hình dạng phụ thuộc vào vật chứa nó.
- 液体是三大物质状态之一，没有确定的形状，但有一定体积，具有移动与转动等运动性。
- Liquid is one of the four fundamental states of matter, and is the only state with a definite volume but no fixed shape. A liquid is made up of tiny vibrating particles of matter, such as atoms and molecules, held together by intramolecular bonds. Water is, by far, the most common liquid on Earth. Like a gas, a liquid is able to flow and take the shape of a container. Some liquids resist compression, while others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly constant density. A distinctive property of the liquid state is surface tension, leading to wetting phenomena. The density of a liquid is usually close to that of a solid, and much higher than in a gas. Therefore, liquid and solid are both termed condensed matter. On the other hand, as liquids and gases share the ability to flow, they are both called fluids. Although liquid water is abundant on Earth, this state of matter is actually the least common in the known universe, because liquids require a relatively narrow temperature/pressure range to exist. Most known matter in the universe is in gaseous form (with traces of detectable solid matter) as interstellar clouds or in plasma form within stars.
- Liquid From Wikipedia, the free encyclopedia This is an old revision of this page, as edited by Mike Rosoft (talk | contribs) at 07:52, 5 May 2013. It may differ significantly from the current revision. (diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff) Jump to: navigation, search For other uses, see Liquid (disambiguation). The formation of a spherical droplet of liquid water minimizes the surface area, which is the natural result of surface tension in liquids. Continuum mechanics BernoullisLawDerivationDiagram. svg Laws[show show] Solid mechanics[show show] Fluid mechanics[show show] Rheology[show show] Scientists[show show] v t e Liquid is one of the four fundamental states of matter (the others being solid, gas, and plasma), and is the only state with a definite volume but no fixed shape. A liquid is made up of tiny vibrating particles of matter, such as atoms and molecules, held together by intramolecular bonds. Water is, by far, the most common liquid on Earth. Like a gas, a liquid is able to flow and take the shape of a container. Some liquids resist compression, while others can be compressed. Unlike a gas, a liquid does not disperse to fill every space of a container, and maintains a fairly constant density. A distinctive property of the liquid state is surface tension, leading to wetting phenomena. The density of a liquid is usually close to that of a solid, and much higher than in a gas. Therefore, liquid and solid are both termed condensed matter. On the other hand, as liquids and gases share the ability to flow, they are both called fluids. Although liquid water is abundant on Earth, this state of matter is actually the least common in the known universe, because liquids require a relatively narrow temperature/pressure range to exist. Most known matter in the universe is in gaseous form (with traces of detectable solid matter) as interstellar clouds or in plasma form within stars. Contents 1 Introduction 2 Examples 3 Applications 4 Mechanical properties 4.1 Volume 4.2 Pressure and buoyancy 4.3 Surfaces 4.4 Flow 4.5 Sound propagation 5 Thermodynamics 5.1 Phase transitions 5.2 Solutions 6 Microscopic properties 6.1 Static structure factor 6.2 Sound dispersion and structural relaxation 6.3 Effects of association 7 References Introduction Thermal image of a sink full of hot water with cold water being added, showing how the hot and the cold water flow into each other. Liquid is one of the three primary states of matter, with the others being solid and gas. A liquid is a fluid. Unlike a solid, the molecules in a liquid have a much greater freedom to move. The forces that bind the molecules together in a solid are only temporary in a liquid, allowing a liquid to flow while a solid remains rigid. A liquid, like a gas, displays the properties of a fluid. A liquid can flow, assume the shape of a container, and, if placed in a sealed container, will distribute applied pressure evenly to every surface in the container. Unlike a gas, a liquid may not always mix readily with another liquid, will not always fill every space in the container, forming its own surface, and will not compress significantly, except under extremely high pressures. These properties make a liquid suitable for applications such as hydraulics. Liquid particles are bound firmly but not rigidly. They are able to move around one another freely, resulting in a limited degree of particle mobility. As the temperature increases, the increased vibrations of the molecules causes distances between the molecules to increase. When a liquid reaches its boiling point, the cohesive forces that bind the molecules closely together break, and the liquid changes to its gaseous state (unless superheating occurs). If the temperature is decreased, the distances between the molecules become smaller. When the liquid reaches its freezing point the molecules will usually lock into a very specific order, called crystallizing, and the bonds between them become more rigid, changing the liquid into its solid state (unless supercooling occurs). Examples Only two elements are liquid at standard conditions for temperature and pressure: mercury and bromine. Four more elements have melting points slightly above room temperature: francium, caesium, gallium and rubidium.[1 1] Metal alloys that are liquid at room temperature include NaK, a sodium-potassium metal alloy, galinstan, a fusible alloy liquid, and some amalgams (alloys involving mercury). Pure substances that are liquid under normal conditions include water, ethanol and many other organic solvents. Liquid water is of vital importance in chemistry and biology; it is believed to be a necessity for the existence of life. Important everyday liquids include aqueous solutions like household bleach, other mixtures of different substances such as mineral oil and gasoline, emulsions like vinaigrette or mayonnaise, suspensions like blood, and colloids like paint and milk. Many gases can be liquefied by cooling, producing liquids such as liquid oxygen, liquid nitrogen, liquid hydrogen and liquid helium. Not all gases can be liquified at atmospheric pressure, for example carbon dioxide can only be liquified at pressures above 5.1 atm. Some materials cannot be classified within the classical three states of matter; they possess solid-like and liquid-like properties. Examples include liquid crystals, used in LCD displays, and biological membranes. Applications Liquids have a variety of uses, as lubricants, solvents, and coolants. In hydraulic systems, liquid is used to transmit power. In tribology, liquids are studied for their properties as lubricants. Lubricants such as oil are chosen for viscosity and flow characteristics that are suitable throughout the operating temperature range of the component. Oils are often used in engines, gear boxes, metalworking, and hydraulic systems for their good lubrication properties.[2 2] Many liquids are used as solvents, to dissolve other liquids or solids. Solutions are found in a wide variety of applications, including paints, sealants, and adhesives. Naptha and acetone are used frequently in industry to clean oil, grease, and tar from parts and machinery. Body fluids are water based solutions. Surfactants are commonly found in soaps and detergents. Solvents like alcohol are often used as antimicrobials. They are found in cosmetics, inks, and liquid dye lasers. They are used in the food industry, in processes such as the extraction of vegetable oil.[3 3] Liquids tend to have better thermal conductivity than gases, and the ability to flow makes a liquid suitable for removing excess heat from mechanical components. The heat can be removed by channeling the liquid through a heat exchanger, such as a radiator, or the heat can be removed with the liquid during evaporation.[4 4] Water or glycol coolants are used to keep engines from overheating.[5 5] The coolants used in nuclear reactors include water or liquid metals, such as sodium or bismuth.[6 6] Liquid propellant films are used to cool the thrust chambers of rockets.[7 7] In machining, water and oils are used to remove the excess heat generated, which can quickly ruin both the work piece and the tooling. During perspiration, sweat removes heat from the human body by evaporating. In the heating, ventilation, and air-conditioning industry (HVAC), liquids such as water are used to transfer heat from one area to another.[8 8] Liquid is the primary component of hydraulic systems, which take advantage of Pascal's law to provide fluid power. Devices such as pumps and waterwheels have been used to change liquid motion into mechanical work since ancient times. Oils are forced through hydraulic pumps, which transmit this force to hydraulic cylinders. Hydraulics can be found in many applications, such as automotive brakes and transmissions, heavy equipment, and airplane control systems. Various hydraulic presses are used extensively in repair and manufacturing, for lifting, pressing, clamping and forming.[9 9] Liquids are sometimes used in measuring devices. A thermometer often uses the thermal expansion of liquids, such as mercury, combined with their ability to flow to indicate temperature. A manometer uses the weight of the liquid to indicate air pressure.[10 10] Mechanical properties Volume Quantities of liquids are commonly measured in units of volume. These include the SI unit cubic metre (m3) and its divisions, in particular the cubic decimetre, more commonly called the litre (1 dm3 = 1 L = 0.001 m3), and the cubic centimetre, also called millilitre (1 cm3 = 1 mL = 0.001 L = 10−6 m3). The volume of a quantity of liquid is fixed by its temperature and pressure. Liquids generally expand when heated, and contract when cooled. Water between 0 °C and 4 °C is a notable exception. Liquids have little compressibility: water, for example, requires a pressure of the order of 200 bar to increase its density by 1/1000. In the study of fluid dynamics, liquids are often treated as incompressible, especially when studying incompressible flow. Pressure and buoyancy Main article: fluid statics In a gravitational field, liquids exert pressure on the sides of a container as well as on anything within the liquid itself. This pressure is transmitted in all directions and increases with depth. If a liquid is at rest in a uniform gravitational field, the pressure, p, at any depth, z, is given by p=\rho g z\, where: \rho\, is the density of the liquid (assumed constant) g\, is the gravitational acceleration. Note that this formula assumes that the pressure at the free surface is zero, and that surface tension effects may be neglected. Objects immersed in liquids are subject to the phenomenon of buoyancy. (Buoyancy is also observed in other fluids, but is especially strong in liquids due to their high density. ) Surfaces Main article: surface science Surface waves in water Unless the volume of a liquid exactly matches the volume of its container, one or more surfaces are observed. The surface of a liquid behaves like an elastic membrane in which surface tension appears, allowing the formation of drops and bubbles. Surface waves, capillary action, wetting, and ripples are other consequences of surface tension. Flow Main article: fluid mechanics Main article: fluid dynamics Viscosity measures the resistance of a liquid which is being deformed by either shear stress or extensional stress. When a liquid is supercooled towards the glass transition, the viscosity increases dramatically! The liquid then becomes a viscoelastic medium that shows both the elasticity of a solid and the fluidity of a liquid, depending on the time scale of observation or on the frequency of perturbation. Sound propagation Main article: speed of sound#Speed of sound in liquids In a fluid the only non-zero stiffness is to volumetric deformation (a fluid does not sustain shear forces). Hence the speed of sound in a fluid is given by c = \sqrt {K/\rho} where K is the bulk modulus of the fluid, and ρ the density. To give a typical value, in fresh water c=1497 m/s at 25 °C. Thermodynamics Phase transitions Main article: boiling Main article: boiling point Main article: melting Main article: melting point A typical phase diagram. The dotted line gives the anomalous behaviour of water. The green lines show how the freezing point can vary with pressure, and the blue line shows how the boiling point can vary with pressure. The red line shows the boundary where sublimation or deposition can occur. At a temperature below the boiling point, any matter in liquid form will evaporate until the condensation of gas above reach an equilibrium. At this point the gas will condense at the same rate as the liquid evaporates. Thus, a liquid cannot exist permanently if the evaporated liquid is continually removed. A liquid at its boiling point will evaporate more quickly than the gas can condense at the current pressure. A liquid at or above its boiling point will normally boil, though superheating can prevent this in certain circumstances. At a temperature below the freezing point, a liquid will tend to crystallize, changing to its solid form. Unlike the transition to gas, there is no equilibrium at this transition under constant pressure, so unless supercooling occurs, the liquid will eventually completely crystallize. Note that this is only true under constant pressure, so e.g. water and ice in a closed, strong container might reach an equilibrium where both phases coexist. For the opposite transition from solid to liquid, see melting. Solutions Main article: solution Liquids can display immiscibility. The most familiar mixture of two immiscible liquids in everyday life is the vegetable oil and water in Italian salad dressing. A familiar set of miscible liquids is water and alcohol. Liquid components in a mixture can often be separated from one another via fractional distillation. Microscopic properties Static structure factor Main article: structure of liquids and glasses Structure of a classical monatomic liquid. Atoms have many nearest neighbors in contact, yet no long-range order is present. In a liquid, atoms do not form a crystalline lattice, nor do they show any other form of long-range order. This is evidenced by the absence of Bragg peaks in X-ray and neutron diffraction. Under normal conditions, the diffraction pattern has circular symmetry, expressing the isotropy of the liquid. In radial direction, the diffraction intensity smoothly oscillates. This is usually described by the static structure factor S(q), with wavenumber q=(4π/λ)sinθ given by the wavelength λ of the probe (photon or neutron) and the Bragg angle θ. The oscillations of S(q) express the near order of the liquid, i.e. the correlations between an atom and a few shells of nearest, second nearest, ... neighbors. A more intuitive description of these correlations is given by the radial distribution function g(r), which is basically the Fourier transform of S(q). It represents a spatial average of a temporal snapshot of pair correlations in the liquid. Radial distribution function of the Lennard-Jones model fluid. Sound dispersion and structural relaxation The above expression for the sound velocity c = \sqrt {K/\rho} contains the bulk modulus K. If K is frequency independent then the liquid behaves as a linear medium, so that sound propagates without dissipation and without mode coupling. In reality, any liquid shows some dispersion: with increasing frequency, K crosses over from the low-frequency, liquid-like limit K_0 to the high-frequency, solid-like limit K_\infty. In normal liquids, most of this cross over takes place at frequencies between GHz and THz, sometimes called hypersound. At sub-GHz frequencies, a normal liquid cannot sustain shear waves: the zero-frequency limit of the shear modulus is G_0=0. This is sometimes seen as the defining property of a liquid.[11 11][12 12] However, just as the bulk modulus K, the shear modulus G is frequency dependent, and at hypersound frequencies it shows a similar cross over from the liquid-like limit G_0 to a solid-like, non-zero limit G_\infty. According to the Kramers-Kronig relation, the dispersion in the sound velocity (given by the real part of K or G) goes along with a maximum in the sound attenuation (dissipation, given by the imaginary part of K or G). According to linear response theory, the Fourier transform of K or G describes how the system returns to equilibrium after an external perturbation; for this reason, the dispersion step in the GHz.. THz region is also called structural relaxation. According the fluctuation-dissipation theorem, relaxation towards equilibrium is intimately connected to fluctuations in equilibrium. The density fluctuations associated with sound waves can be experimentally observed by Brillouin scattering. On supercooling a liquid towards the glass transition, the crossover from liquid-like to solid-like response moves from GHz to MHz, kHz, Hz, ... ; equivalently, the characteristic time of structural relaxation increases from ns to μs, ms, s, ... This is the microscopic explanation for the above mentioned viscoelastic behaviour of glass-forming liquids. Effects of association The mechanisms of atomic/molecular diffusion (or particle displacement) in solids are closely related to the mechanisms of viscous flow and solidification in liquid materials. Descriptions of viscosity in terms of molecular "free space" within the liquid[13 13] were modified as needed in order to account for liquids whose molecules are known to be "associated" in the liquid state at ordinary temperatures. When various molecules combine together to form an associated molecule, they enclose within a semi-rigid system a certain amount of space which before was available as free space for mobile molecules. Thus, increase in viscosity upon cooling due to the tendency of most substances to become associated on cooling.[14 14] Similar arguments could be used to describe the effects of pressure on viscosity, where it may be assumed that the viscosity is chiefly a function of the volume for liquids with a finite compressibility. An increasing viscosity with rise of pressure is therefore expected. In addition, if the volume is expanded by heat but reduced again by pressure, the viscosity remains the same. The local tendency to orientation of molecules in small groups lends the liquid (as referred to previously) a certain degree of association. This association results in a considerable "internal pressure" within a liquid, which is due almost entirely to those molecules which, on account of their temporary low velocities (following the Maxwell distribution) have coalesced with other molecules. The internal pressure between several such molecules might correspond to that between a group of molecules in the solid form. References ^ Theodore Gray, The Elements: A Visual Exploration of Every Known Atom in the Universe New York: Workman Publishing, 2009 p. 127 ISBN 1-57912-814-9 ^ Theo Mang, Wilfried Dressel ’’Lubricants and lubrication’’, Wiley-VCH 2007 ISBN 3-527-31497-0 ^ George Wypych ’’Handbook of solvents’’ William Andrew Publishing 2001 pp. 847–881 ISBN 1-895198-24-0 ^ N. B. Vargaftik ’’Handbook of thermal conductivity of liquids and gases’’ CRC Press 1994 ISBN 0-8493-9345-0 ^ Jack Erjavec ’’Automotive technology: a systems approach’’ Delmar Learning 2000 p. 309 ISBN 1-4018-4831-1 ^ Gerald Wendt ’’The prospects of nuclear power and technology’’ D. Van Nostrand Company 1957 p. 266 ^ ’’Modern engineering for design of liquid-propellant rocket engines’’ by Dieter K. Huzel, David H. Huang – American Institute of Aeronautics and Astronautics 1992 p. 99 ISBN 1-56347-013-6 ^ Thomas E Mull ’’HVAC principles and applications manual’’ McGraw-Hill 1997 ISBN 0-07-044451-X ^ R. Keith Mobley Fluid power dynamics Butterworth-Heinemann 2000 p. vii ISBN 0-7506-7174-2 ^ Bela G. Liptak ’’Instrument engineers’ handbook: process control’’ CRC Press 1999 p. 807 ISBN 0-8493-1081-4 ^ Born, Max (1940). "On the stability of crystal lattices". Mathematical Proceedings (Cambridge Philosophical Society) 36 (2): 160–172. doi:10.1017.2FS0305004100017138. ^ Born, Max (1939). "Thermodynamics of Crystals and Melting". Journal of Chemical Physics 7 (8): 591–604. doi:10.1063.2F1.1750497. ^ D.B. Macleod (1923). "On a relation between the viscosity of a liquid and its coefficient of expansion". Trans. Farad. Soc. 19: 6. doi:10.1039/tf9231900006. ^ G. W Stewart (1930). "The Cybotactic (Molecular Group) Condition in Liquids; the Association of Molecules". Phys. Rev. 35 (7): 726. Bibcode:1930PhRv...35..726S. doi:10.1103/PhysRev.35.726. [hide hide] v t e States of matter (classic) State Solid Liquid Gas / Vapor Plasma Phase change - en. svg Low energy Bose–Einstein condensate Fermionic condensate Degenerate matter Quantum Hall Rydberg matter Strange matter Superfluid Supersolid High energy QCD matter Quark–gluon plasma Supercritical fluid Other states Colloid Glass Liquid crystal Magnetically ordered Antiferromagnet Ferrimagnet Ferromagnet String-net liquid Superglass Transitions Boiling Boiling point Condensation Critical line Critical point Crystallization Deposition Evaporation Flash evaporation Freezing Ionization Lambda point Melting Melting point Recombination Regelation Saturated fluid Sublimation Supercooling Triple point Vaporization Vitrification Quantities Enthalpy of fusion Enthalpy of sublimation Enthalpy of vaporization Latent heat Latent internal energy Trouton's ratio Volatility Concepts Binodal Compressed fluid Cooling curve Equation of state Leidenfrost effect Mpemba effect Order and disorder (physics) Spinodal Superconductivity Superheated vapor Superheating Thermo-dielectric effect Lists List of states of matter
- liq·uid /ˈlikwid/ Adjective Having a consistency like that of water or oil, i.e. , flowing freely but of constant volume. Noun A liquid substance: "drink plenty of liquids". Synonyms adjective. fluid - fluent noun. fluid - liquor - water
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- El líquid és un dels estats de la matèria més quotidians. És un fluid, dins del qual els àtoms o molècules que el formen es mouen lliurement en el seu interior. A diferència dels gasos (també fluids), les distàncies entre les seves molècules són casi invariants pel que se'ls considera pràcticament incompressibles. En canvi, la matèria en estat líquid és fàcilment deformable. La superfície és una superfície lliure en què el líquid no està limitat per un contenidor.
- Kapalina neboli kapalná látka je jedno ze skupenství látek, při kterém jsou částice látky relativně blízko sebe, ale nejsou vázány v pevných polohách a mohou se pohybovat v celém objemu. Kinetická energie částic kapaliny je malá ve srovnání s vazební potenciální energií, takže částice se vzájemně udržují v určitých rovnovážných polohách, kolem kterých vykonávají kmitavý pohyb. Tyto rovnovážné polohy se u kapalin mohou přemisťovat, tzn. dochází k přemísťování částic v celém objemu látky.
- Eine Flüssigkeit ist Materie im flüssigen Aggregatzustand. Nach einer makroskopischen Definition handelt es sich um einen Stoff, der einer Formänderung so gut wie keinen, einer Volumenänderung hingegen einen recht großen Widerstand entgegensetzt (der Stoff ist nahezu inkompressibel).
- El líquido es un estado de agregación de la materia en forma de fluido altamente incompresible (lo que significa que su volumen es, muy aproximadamente, constante en un rango grande de presión).
- Neste on yksi aineen olomuodoista. Sulamispisteessä kiinteä aine sulaa ja muuttuu nesteeksi. Nesteessä rakenneosat siirtyilevät, mutta niiden väliset vuorovaikutukset ovat voimakkaampia kuin kaasufaasissa. Aine on nesteenä, kun se on kiehumis- ja sulamispisteiden välissä. Neste on usein pisaroissa tai lammikoissa pintajännityksen vuoksi. Viskositeetti kuvaa nesteen sisäisen virtauksen vastustuksen voimakkuuden. Ns. täydellinen neste tarkoittaa nestettä, jossa ei ole lainkaan kitkaa.
- La phase liquide est un état de la matière. Sous cette forme, la matière est facilement déformable mais difficilement compressible. Le liquide est une forme de fluide : les molécules sont faiblement liées, ce qui rend les liquides parfaitement déformables.
- A folyadék (ideális folyadéknak tekintve) az anyagnak azon halmazállapota, amelyben az anyag felveszi a tárolásra szolgáló edény alakját, megtartja a térfogatát és nem képes csavaróerők továbbítására. Gyakorlatilag összenyomhatatlan, részecskéi állandóan, tetszőleges módon helyet változtatnak. A részecskék – sok szilárd anyagtól eltérően – rendezetlenül helyezkednek el, eltekintve egyfajta enyhe fokú, laza rendezettségtől.
- Il liquido è uno degli stati della materia.
- 液体（えきたい）は物質の三態の一つである。気体と同様に流動的で、容器に合わせて形を変える。液体は気体に比して圧縮性が小さい。気体とは異なり、容器全体に広がることはなく、ほぼ一定の密度を保つ。液体特有の性質として表面張力があり、それによって「濡れ」という現象が起きる。 液体の密度は一般に固体のそれに近く、気体よりもはるかに高い密度を持つ。そこで液体と固体をまとめて「凝集系」などとも呼ぶ。一方で液体と気体は流動性を共有しているため、それらをあわせて流体と呼ぶ。
- 액체(液體)는 간단히 말해 물질의 상으로 물처럼 부피는 일정하지만 자유롭게 모양을 바꿀 수 있는 유체를 말한다. 구체적으로 말해 액체는 50℃에서 300kPa(3bar) 이하의 증기압을 가지고, 20℃ 및 101.3kPa에서 완전히 가스상이 아니며 또한 101.3kPa에서 녹는점 또는 초기 녹는점이 20℃ 이하인 물질을 말한다. 끓는점 이상의 온도에서 기체로, 어는점 이하에서 고체로 상을 바꾼다. 액체는 고체와 달리 어떤 모양의 그릇에나 들어갈 수가 있다. 이것은 액체를 이루고 있는 입자가 고체의 경우보다 상호간의 결합력이 약하여 움직이기 쉽기 때문이다. 또, 기체를 주사기에 넣고 구멍을 막은 다음 피스톤을 밀었다가 뺐다가 하면 기체의 부피가 변한다. 그러나 액체는 이와 같이 해도 부피가 변하지 않는다. 이것은 액체를 이루고 있는 입자의 틈새가 기체의 경우보다 훨씬 작기 때문이다.
- Vloeistof is een van de aggregatietoestanden waarin stoffen kunnen voorkomen. In deze toestand is de stof vloeibaar, in de scheikunde ook wel afgekort met l (liquid). Afhankelijk van de temperatuur verandert de viscositeit van de stof van stroperig tot dun vloeibaar. Ook kan de stof bij zeer lage temperatuur supervloeibaar worden. Door de oppervlaktespanning van een vloeistof te verlagen kan deze zeer dun uitlopen en luchtbellen vormen.
- Væske betegner en aggregattilstand (fase) som har fast volum men ikke fast form. I likhet med gasser, kan væsker flyte (strømme) og endre form på vilkårlig måte, men vil i motsetning til gasser ikke fylle tilgjengelig volum i en beholder. Faststoff har tilnærmet fast volum, men kan i motsetning til væske ikke endre form på vilkårlig måte. Væsker kan flyte mer eller mindre lett, hvor vann er et eksempel på en væske som flyter lett, mens honning er seigtflytende.
- Ciecz – stan skupienia materii – pośredni między ciałem stałym a gazem, w którym ciało fizyczne trudno zmienia objętość, a łatwo zmienia kształt. Wskutek tego ciecz przyjmuje kształt naczynia, w którym się znajduje, ale w przeciwieństwie do gazu nie rozszerza się, aby wypełnić je całe. Powierzchnia styku cieczy z gazem lub próżnią nazywa się powierzchnią swobodną cieczy. Istnienie cieczy ogranicza od strony niskich temperatur temperatura krzepnięcia, a od wysokich temperatura wrzenia.
- O estado líquido é um estado da matéria no qual a distância entre suas moléculas é suficiente para se adequar a qualquer meio (tomando sua forma), porém sem alterar o volume. Um líquido é uma das cinco principais fases da matéria. E dito um fluido aquilo cuja a forma é usualmente determinada por aquilo que o contem.
- Жи́дкость — одно из агрегатных состояний вещества. Основным свойством жидкости, отличающим её от других агрегатных состояний, является способность неограниченно менять форму под действием касательных механических напряжений, даже сколь угодно малых, практически сохраняя при этом объём.
- Vätska eller flytande form är ett aggregationstillstånd för kondenserad materia, som kännetecknas av att tillståndet inte har elastisk deformation vid skjuvning. Vanliga vätskor har låg viskositet så att en vätska i en bägare snabbt får samma form som bägaren. Symbolen (l) används för att ange att ett ämne är i flytande form. Symbolen sätts tätt intill, i samma teckengrad och i rak stil, det ämne eller den förening den tillhör: H2O(l) betecknar flytande vatten.
- Рідина́ — один з основних агрегатних станів речовини поряд із газом та твердим тілом. Від газу рідина відрізняється тим, що зберігає свій об'єм, а від твердого тіла тим, що не зберігає форму. Рух рідин та тіл в рідинах вивчає розділ фізики гідродинаміка, будову та фізичні властивості рідин — фізика рідин, складова частнина молекулярної фізики.
- Chất lỏng là một trạng thái vật chất khá phổ biến. Chất lỏng là một chất lưu mà các phân tử cấu tạo nên nó có liên kết không chặt so với liên kết rắn và có hình dạng phụ thuộc vào vật chứa nó.
- 液体是三大物质状态之一，没有确定的形状，但有一定体积，具有移动与转动等运动性。
- Liquid is one of the four fundamental states of matter, and is the only state with a definite volume but no fixed shape. A liquid is made up of tiny vibrating particles of matter, such as atoms and molecules, held together by intramolecular bonds. Water is, by far, the most common liquid on Earth. Like a gas, a liquid is able to flow and take the shape of a container. Some liquids resist compression, while others can be compressed.
- liq·uid /ˈlikwid/ Adjective Having a consistency like that of water or oil, i.e. , flowing freely but of constant volume. Noun A liquid substance: "drink plenty of liquids". Synonyms adjective. fluid - fluent noun. fluid - liquor - water
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