A list of common liquids includes water, milk, blood, wine, coffee and honey. Other liquids include urine, alcohol and gasoline. Mercury and bromine are the only two elements that are liquid at normal conditions of temperature and pressure.
Liquid is one of the four states of matter; the other three forms are solid, gas and plasma. It is the only form of matter that has a definite volume but no definite shape. A liquid is an almost incompressible fluid that takes the shape of its container but maintains a fairly constant volume independent of pressure. It is composed of small vibrating particles of matter including atoms, joined together by intermolecular bonds. The most important and common liquid on earth is water, which is extremely essential for the existence of life. A liquid can be formed by heating a solid above its melting point.
Some metal alloys are also liquid at room temperature, including sodium-potassium alloy (NaK) and amalgams (alloys of mercury). Water, ethanol and most organic solvents are pure substances that are liquid at standard conditions. Most acids, inorganic nonaqueous solvents and water constitute inorganic liquids. Liquefaction of many gases through cooling produces liquids including liquid hydrogen, liquid oxygen and liquid nitrogen. Liquids have several uses as lubricants, coolants and solvents, and are also used as power transmitters in hydraulic systems.