the phenomenon of an element existing in two or more physical forms

chemical process in which one atom or ion or group changes places with another

the formation of crystals

the phenomenon of forming chemical bonds

(chemistry) the existence of different kinds of crystal of the same chemical compound

(chemistry) the three traditional states of matter are solids (fixed shape and volume) and liquids (fixed volume and shaped by the container) and gases (filling the container)

an exchange produced by the chemical action of radiant energy (especially light)

a powdery deposit on a surface

(chemistry) the property of certain substances that enables them to exist in two distinct crystalline forms

(physical chemistry) a distinct state of matter in a system; matter that is identical in chemical composition and physical state and separated from other material by the phase boundary

the state in which a substance exhibits a characteristic readiness to flow with little or no tendency to disperse and relatively high incompressibility

the state in which a substance has no tendency to flow under moderate stress; resists forces (such as compression) that tend to deform it; and retains a definite size and shape

the state of matter distinguished from the solid and liquid states by: relatively low density and viscosity; relatively great expansion and contraction with changes in pressure and temperature; the ability to diffuse readily; and the spontaneous tendency to become distributed uniformly throughout any container

(physical chemistry) a fourth state of matter distinct from solid or liquid or gas and present in stars and fusion reactors; a gas becomes a plasma when it is heated until the atoms lose all their electrons, leaving a highly electrified collection of nuclei and free electrons

all phenomena that are not artificial