Unit 1: Exploring Matter Section 1.3: Physical and Chemical Changes

Physical Change In a physical change, the substance involved remains the same. The only thing that can change in a physical change is the substance’s state. For example, what happens when the wax from a melted candle cools? It turns back into a solid

Chemical Change In a chemical change, the original substance is changed into one or more different substances. The new substances have different properties from the original substance. There are 5 clues you should look for in any chemical change: A new colour appears Bubbles of gas are formed Heat or light is given off A solid material (called a precipitate) forms in a liquid The reaction can not be reversed

What change is described by each of the following statements? A glow stick begins to glow. Water is boiled. An egg is fried on a stove. Wax from a candle melts. A lollipop melts in the sun. An iron nail rusts in the rain. Blood permanently stains your shirt. Milk left outside goes sour. chemical physical chemical physical physical chemical chemical chemical