Notes 2.1 Physical and Chemical Properties and Changes

A.1 Properties Make the Difference Every substance has characteristic properties that distinguish it from other substances Physical properties Described by senses - Color, density, odor, touch Can be determined without altering the chemical makeup of the material Also influence use via ability to undergo changes Examples - melting, boiling, bending

A.1 Properties Make the Difference Physical change Material remains the same chemically, but the form is different Usually reversible Ex. Tearing, cutting, bending, filtering, melting boiling

A.1 Properties Make the Difference Chemical change When a substance changes into one or more new substances Not reversible Rusting- tendency of a metal to form an oxide Evidences for a chemical change Formation of gas Formation of a precipitate (solid) Permanent color change Production of heat and light

A.1 Properties Make the Difference Chemical properties Relate to any kind of chemical changes Flammability, Reactivity, Oxidizer