Chapter 2–3 Warm Up Changes of Matter 1. What is 2 physical and 2 chemical properties? 2. Describe density. 3. What is the unit that density is measured in? 4. What does an object need in order to burn?

Chapter 2-3 Matter Changes of Matter

Physical Changes Physical Change – change of matter from one form to another without a change in chemical properties Breaking a stick

Physical Changes Dissolving in water Melting Sanding Crushing

Physical Change Physical changes do not change a substance's identity Quartz to sand Gold nugget to gold ring

Dissolving Dissolving is a physical change

Using Physical Properties to Separate Size - one physical property often used to separate substances. Magnetic attraction - can be used to separate substances in a mixture.

Distillation Process for separating substances in a mixture Evaporating a liquid and recondensing its vapor is distillation.

Centrifuge Separates part of blood

Chemical Changes Chemical Change – occurs when a substance changes composition by forming a new substance

Chemical Changes Respiration Digestion

Chemical Changes Form new substances with new properties Baking a cake

Chemical Changes Chemical changes can be detected Color change Odor Fizzing Sound Heat Light

Chemical Change Chemical changes cannot be reversed by physical changes Unbake a cake?

Chemical Changes Compounds can be broken down through chemical changes Carbonic acid give pop the fizz Breaks down into carbon dioxide and water