Physical and Chemical Changes Unit IIPart 2 Concept

Physical and Chemical Changes Unit II—Part 2

Concept of Change l Change: the act of altering a substance

Physical Change l Physical change: a change that occurs that does not change the identity of the substance u Melting ice u Freezing Kool-aid u Tearing paper u Dissolving sugar in water

Chemical Changes l Chemical change: a change that occurs causing the identity of the substance to change Burning u Digesting food u Rusting u l A chemical change is called a chemical reaction

Chemical Changes Cont’d l Indicators of a chemical change: • • • Production of light Production of heat Production of a gas Color change Formation of a precipitate

Is it Physical or Chemical? Physical Glass breaking

Is it Physical or Chemical? Chemical Burning leaves

Is it Physical or Chemical? Physical Butter melting

Is it Physical or Chemical? Chemical Fireworks exploding

Is it Physical or Chemical? Physical Pouring milk on cereal

Is it Physical or Chemical? Physical Mowing a lawn

Is it Physical or Chemical? Physical Separating sand gravel

Is it Physical or Chemical? Chemical Bleaching hair

Is it Physical or Chemical? Chemical Frying an egg

Is it Physical or Chemical? Physical Hammering nails into wood to frame a house

Is it Physical or Chemical? Chemical Burning toast

Is it Physical or Chemical? Physical Mixing powdered Kool-Aid with water

Is it Physical or Chemical? Physical Adding salt to water to gargle

Is it Physical or Chemical? Chemical Food spoiling

Is it Physical or Chemical? Chemical Rusting bicycle

Is it Physical or Chemical? Physical Melting ice cream

Changes Physical Chemical

Properties Physical Chemical