II. Properties & Changes in Matter

B. Physical vs. Chemical Physical Property Inherent characteristics that can be observed without altering the identity (composition) of the substance Chemical Property describes the ability of a substance to undergo changes in identity by either reacting with something else of decomposition.

Physical Properties Extensive Property depends on the amount of matter present Mass, length, volume Intensive Property depends on the identity of substance, not the amount Density (g/ml), color, melting and boiling points

A. Extensive vs. Intensive Examples: boiling point volume mass density conductivity

B. Physical vs. Chemical Examples: melting point flammable density magnetic tarnishes in air

B. Physical vs. Chemical Physical Change changes the form of a substance without changing its identity Size, shape, phase properties remain the same Chemical Change changes the identity of a substance products have different properties

B. Physical vs. Chemical Signs of a Chemical Change change in color or odor formation of a gas formation of a precipitate (solid) change in light or heat

Law of Conservation of Mass In a chemical change, there is no change in the total mass of the substances involved. Mass of Reactants = Mass of Products Mercury(II)Oxide Mercury + Oxygen

B. Physical vs. Chemical Examples: rusting iron dissolving in water burning a log melting ice grinding spices