State of matter
Distinct forms of matter defined by particle arrangement and behavior.
A state of matter, also referred to as a phase of matter, is one of the distinct forms in which matter can exist. Four classical states—solid, liquid, gas, and plasma—are observable in everyday life, each distinguished by the arrangement and collective behavior of its component particles. Beyond these, a wide variety of additional states are known, including those that occur only under extreme conditions, such as Bose–Einstein condensates and quark–gluon plasma.
- classical_states
- solid, liquid, gas, plasma
- solid_definition
- particles tightly packed in fixed positions; definite shape and volume
- liquid_definition
- particles close but mobile; fixed volume, shape of container
- gas_definition
- particles far apart and free; fills container shape and volume
- plasma_definition
- similar to gas but contains charged particles (ions and free electrons) that respond to electric and magnetic fields
- most_abundant_state
- plasma (99% of ordinary matter in the universe)
Lore & Background
The four classical states of matter are solid, liquid, gas, and plasma. In a solid, particles are tightly packed and held in fixed positions, giving a definite shape and volume. In a liquid, particles remain close but can move past one another, maintaining a fixed volume while adapting to the container's shape. In a gas, particles are far apart and move freely, expanding to fill both the shape and volume of the container. Plasma is similar to a gas but contains charged particles (ions and free electrons) that move independently and respond to electric and magnetic fields.
Reader's Guide
The concept of state of matter is fundamental to physics and chemistry, describing how matter organizes under different conditions. The four classical states—solid, liquid, gas, and plasma—are observable in everyday life, with plasma being the most abundant form in the universe, composing all stars. Beyond these, additional states exist, such as liquid crystals, which exhibit properties of both solids and liquids, and magnetic states like ferromagnetism, which depend on spin alignment rather than spatial arrangement. Some states occur only under extreme conditions, including Bose–Einstein condensates (extreme cold), neutron-degenerate matter (extreme density), and quark–gluon plasma (extremely high energy). The term 'phase' is sometimes used synonymously with state of matter, but a single compound can form multiple phases in the same state, as with ice having multiple crystal structures. Phase transitions mark changes between states, often with abrupt property changes, and intermediate steps are called mesophases, exploited in liquid crystal technology.
Did You Know?
- Plasma is by far the most abundant of the four fundamental states, composing 99% of all ordinary matter in the universe.
- Ice has fifteen known crystal structures, or solid phases, which exist at various temperatures and pressures.
- A supercritical fluid has the physical properties of a gas but its high density confers solvent properties in some cases.
- Magnetic states such as ferromagnetism do not depend on the spatial arrangement of atoms, but on the alignment of their intrinsic magnetic moments (spins).
More in Thermodynamics And Statistical Mechanics 1-22
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