2 Warm up What is matter? What are the three states of matter? Fill in the tables with one difference between each of the following:Element and compoundCompound and mixture
3 Objectives Identify substances using physical properties. Compare and contrast physical and chemical changes.Identify chemical changes.Determine how the law of conservation of mass applies to chemical changes.
4 IntroductionWhat properties can be used to describe the items in the following figure?
5 Physical propertiesAny characteristic of a material that you can observe without changing the identity of the substance.Examples of physical properties are:Color, size, shape, mass, volume, density, melting point, boiling point, attraction to magnet and the ability to flow.
6 Some physical properties describe the behavior of materials or substances. Examples are copper and gold.
7 Using physical properties to separate How can you separate a mixture of iron filling and sand?How can you separate a mixture of seeds and sand?
14 Clues of chemical change Smell,change in colorformation of gasformation of a precipitatepop soundproduction of heatcoolingformation of bubbles, light, foaming…
15 Using chemical change to separate Cleaning tarnished silver.Tarnish is a chemical reaction between silver metal and sulfur compounds in the air.We can remove tarnish by placing the tarnished silver item in warm water, baking soda and aluminum foil.Many metals are separated from their ores and then purified by using chemical changes.
16 The conservation of mass Matter is neither created nor lost during a chemical change.The mass of all substances that are present before a chemical change equals the mass of all substances that remain after the chemical change.Example: when a chemical reaction takes place, the total mass of reactants equals the total mass of products. If 18 g of hydrogen react completely with 633 g of chlorine, how many grams of HCl are formed?H2 + Cl HCl
17 Wrap up What is a physical property? What is a chemical property? Distinguish between a physical and chemical change.Examples of a physical and chemical change and properties.Law of conservation of mass
18 Practice problem page: 463 # 1 and 2 Quiz in section 15.2 Home WorkPage: 465 # 1 to 6Practice problem page: 463 # 1 and 2Quiz in section 15.2