Liquid
See also Solid
Liquid is a state of matter in which the constituent molecules are not constrained in their relative location to each other. In the way it flows, a liquid behaves similarly to a gas. Unlike a gas it occupies a nearly fixed volume, regardless of the pressure. Where in contact with a gas, a liquid will be bounded by a well-defined surface, whose strength is described by a property called surface tension. Surface tension is responsible for most of the phenomena we associate with liquids, including wetting to surfaces, and the tendency of small droplets to form spheres.
Water is a well known liquid at room temperature and pressure.
- Snippet from Wikipedia: Liquid
Liquid is a state of matter with a definite volume but no fixed shape. Liquids adapt to the shape of their container and are nearly incompressible, maintaining their volume even under pressure. The density of a liquid is usually close to that of a solid, and much higher than that of a gas. Therefore, liquid and solid are classified as condensed matter. Meanwhile, since both liquids and gases can flow, they are categorized as fluids.
A liquid is composed of atoms or molecules held together by intermolecular bonds of intermediate strength. These forces allow the particles to move around one another while remaining closely packed. In contrast, solids have particles that are tightly bound by strong intermolecular forces, limiting their movement to small vibrations in fixed positions. Gases, on the other hand, consist of widely spaced, freely moving particles with only weak intermolecular forces.
As temperature increases, the molecules in a liquid vibrate more intensely, causing the distances between them to increase. At the boiling point, the cohesive forces between the molecules are no longer sufficient to keep them together, and the liquid transitions into a gaseous state. Conversely, as temperature decreases, the distance between molecules shrinks. At the freezing point, the molecules typically arrange into a structured order in a process called crystallization, and the liquid transitions into a solid state.
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 either gaseous (as interstellar clouds) or plasma (as stars).