The formation of a spherical droplet of liquid water minimizes the surface area, which is the natural result of surface tension in liquids. The density of a liquid is usually close to that of a solid, and much higher liquid milk banana that of 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.

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 four primary states of matter, with the others being solid, gas and plasma. Unlike a solid, the molecules in a liquid have a much greater freedom to move. 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. If liquid is placed in a bag, it can be squeezed into any shape.

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. This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Only two elements are liquid at standard conditions for temperature and pressure: mercury and bromine. 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, and it is necessary for all known forms of life. Inorganic liquids include water, magma, inorganic nonaqueous solvents and many acids. Many gases can be liquefied by cooling, producing liquids such as liquid oxygen, liquid nitrogen, liquid hydrogen and liquid helium. Some materials cannot be classified within the classical three states of matter. In addition to the top surface, surfaces also form between the liquids, requiring a tension breaker to recombine the wax droplets at the bottom.

Liquids have a variety of uses, as lubricants, solvents, and coolants. 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. 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.

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. 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. Similarly, liquids are often used in cooking for their better heat-transfer properties. Liquid is the primary component of hydraulic systems, which take advantage of Pascal’s law to provide fluid power.

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. Quantities of liquids are measured in units of volume. The volume of a quantity of liquid is fixed by its temperature and pressure. Liquids generally expand when heated, and contract when cooled. On the other hand, liquids have little compressibility.