Properties Changes of Matter Properties of Matter Physical

Properties of Matter � Physical Property- a property that can be observed and measured

Properties of Matter � Chemists use properties to identify and separate matter. More than

Changes in Matter �A physical change does not change the composition or identity of

Condense Freeze Evaporate Melt Solid Liquid Gas

Changes in Matter � Sublimation is a process in which a solid changes directly

Changes in Matter �A chemical change occurs when one or more substances are changed

Indications of chemical change 1 Production of heat, light, sound, or electricity 2. )

Energy Changes • Some changes in matter release energy. • For example, the explosion

Energy Changes • A change in matter in which energy is absorbed from the

Energy Changes • A change in matter in which energy is released is an

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Properties & Changes of Matter

Properties of Matter � Physical Property- a property that can be observed and measured without changing the identity of the substance. � Examples? � Chemical Property-relates to a substance’s ability to undergo changes that transform it into different substances. � Examples?

Properties of Matter � Chemists use properties to identify and separate matter. More than one property must be used for identification. � Intensive Properties – do not depend on the amount of matter present Ex. Melting pt. , boiling pt, density, conduct electricity � Extensive Properties – depend on the amount of matter present Ex. Volume, mass

Changes in Matter �A physical change does not change the composition or identity of the substance. �Examples? �Boiled water is still water. �All phase changes are physical changes

Condense Freeze Evaporate Melt Solid Liquid Gas

Changes in Matter � Sublimation is a process in which a solid changes directly to a gas without going through the liquid phase. � Examples: dry ice CO 2

Changes in Matter �A chemical change occurs when one or more substances are changed into new substances. � Reactants- substances that react � Products- substances that form � Products have NEW PROPERTIES

Indications of chemical change 1 Production of heat, light, sound, or electricity 2. ) Production of a gas 3. ) Formation of a precipitate 4. ) A change in color 5. ) A change in odor

Energy Changes • Some changes in matter release energy. • For example, the explosion that occurs when hydrogen and oxygen react to form water is a release of energy. • Heat energy and light energy are released as the reaction takes place.

Energy Changes • A change in matter in which energy is absorbed from the surroundings is an endothermic process (heat enters). • EXAMPLES: melting ice & boiling water • When barium hydroxide reacts ammonium nitrate are mixed the test-tube feels cold to touch because energy has been absorbed

Energy Changes • A change in matter in which energy is released is an exothermic process (heat exits). • Examples: freezing water & condensation • Burning of paper gives off heat to the surroundings.