A phase has the following characteristics:
• a phase has the same structure or atomic arrangement throughout
• a phase has roughly the same composition and properties throughout
• there is a definite interface between the phase and any surrounding or adjoining phases
A phase describes and is a specific state of matter, such as solid, liquid, or gas. It is uniform in composition and physical state and separated from other phases by definite boundaries. Can also be thought of as a quantity of matter that is homogeneous throughout. It should be noted that in chemistry a phase may also constitute a component, where a mixture can be comprised of different components.
For examle: solid H2O is a phase, liquid H2O is a phase, and gaseous H2O is a phase. Each has unique atomic arrangement, unique properties, and a definite boundary between each form.
Note: the word phase may be used in other engineering contexts that do not fit this definition.
In chemistry, a phase is a sample of matter that is uniform in composition and physical state and separated from other phases by definite boundaries.
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