Properties and Changes Physical vs. Chemical

Physical Properties Characteristic properties Can be determined without changing substance’s chemical makeup Examples ▫Color ▫Density ▫Odor ▫Solubility ▫Texture

Physical Properties Properties used to describe matter can be classified as extensive or intensive properties. An extensive property is a property that depends on the amount of matter in a sample ▫Ex.: mass, volume, density An intensive property is a property that depends on the type of matter in a sample, not the amount of matter. Ex.: color, odor, absorbancy

Chemical Properties Play important roles in determining substances’ usefulness Relate to the potential of a substance to undergo chemical changes Examples: ▫heat of combustion ▫reactivity with water ▫pH

Physical Changes Changes where the identity of the substance stays the same Examples: ▫Melting ▫Boiling ▫Bending ▫Cutting

Chemical Changes Transform substances into new substances Examples of signs of chemical change: ▫Rusting ▫Gas formation ▫Temperature change ▫Color change

Classify each statement Physical or chemical property? ▫Pure metals have high luster (shiny, reflect light) ▫Surfaces of some metals become dull when exposed to air ▫Milk turns sour if left too long at room temperature ▫Diamonds are hard enough to be used on drill bits ▫Metals can be drawn into wires (ductile) ▫Bread dough increases in volume if it is allowed “rise” ▫Metals are better conductors of heat & electricity than nonmetals

Classify each statement Physical or chemical property? ▫Pure metals have high luster (shiny, reflect light) P ▫Surfaces of some metals become dull when exposed to air C ▫Milk turns sour if left too long at room temperature C ▫Diamonds are hard enough to be used on drill bits P ▫Metals can be drawn into wires (ductile) P ▫Bread dough increases in volume if it is allowed “rise” C ▫Metals are better conductors of heat & electricity than nonmetals P

Matter Anything that has mass Composed of atoms 4 phases / states ▫Solid ▫Liquid ▫Gas ▫Plasma

Phases / States of Matter Solid ▫Fixed volume ▫Fixed shape Gas ▫Takes volume of container ▫Takes shape of container Liquid ▫Fixed volume ▫Takes shape of container Plasma ▫Like superheated gas  Ex.: sun  Made of free electrons and ions

Standards NGSSS ▫SC.912.P.8.2 Differentiate between physical and chemical properties and physical and chemical changes of matter. ▫SC.912.P.8.5 Relate properties of atoms and their position in the periodic table to the arrangement of their electrons.