sample of matter with constant composition and distinct chemical properties.

a substance that cannot be subdivided using chemical means; identified by the number of protons in its atoms.

chemical species formed when two or more atoms form a chemical bond.

combination of two or more substances such that each retains its separate chemical identity (e.g., salt and flour).

state of matter characterized by high degree of organization, with a stable shape and volume.

state of matter characterized by having a definite volume but not a definite shape.

state of matter characterized by having neither a defined shape nor defined volume.

state of matter with no defined shape or volume consisting of ions and electrons.

homogeneous phase of matter (e.g., solid, liquid).

homogeneous mixture of two or more substances.

homogenous mixture in which dispersed particles do not settle out.

heterogeneous mixture of solid particles in a fluid.

energy contained in the internal structure of an atom or molecule.

property of matter that is independent of the quantity of matter in a sample.

property of matter that depends on the quantity of matter that is present.

characteristic of matter that may be observed and measured without changing the identity of the sample.

characteristic which may be observed when matter undergoes a chemical change.

change that alters the form of matter but not its chemical composition.

process by which one or more substances are altered to form new substances.

phase change of matter from solid to liquid.

process in which a liquid changes to a solid.

phase transition from the liquid to gas state.

state of matter change from vapor phase to liquid phase.

phase transition from solid phase directly to vapor phase.