Describing Matter

Physical property- characteristic of a material that you can observe without changing the substance.

E.g. colour, size, shape, density, melting point, boiling point

Chemical property- characteristics of a substance that indicates whether it can undergo a certain chemical change.

E.g. flammable, combustible, may react to light

Physical change- a change in size, shape or state of matter; substance does not change identity when it undergoes a physical change.

E.g. melting ice, cutting paper, breaking glass.

Chemical change- a change in one substance to another substance.

E.g. fireworks explode, rusting metal

Law of Conservation of Mass: says that the mass of all substances present before a chemical change equals the mass of all substances after the change.