any natural phenomenon involving chemistry (as changes to atoms or molecules)

of definite shape and volume; firm; neither liquid nor gaseous

existing as or having characteristics of a liquid; especially tending to flow

existing as or having characteristics of a gas

the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions

(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

of definite shape and volume; firm; neither liquid nor gaseous

existing as or having characteristics of a liquid; especially tending to flow

existing as or having characteristics of a gas

the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions