Properties and Changes Physical vs Chemical Physical Properties

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 ▫ p. H

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.