Chapter 2 (new textbook!) CHEMISTRY is the study of the properties, composition and reactions of matter

Properties of Matter - Matter is anything that has mass and volume. Mass is the amount of matter in a substance or object. Mass is often measured in grams or kilograms. Volume is the amount of space a substance or an object occupies. Volume is often measured in litres.

1. Describing Matter by physical properties - Using Physical Properties ( a characteristic that can be observed or measured without changing the type of matter it is) Observations can be qualitative or quantitative Copy down table 1.1 p. 22 from textbook, understand all words

Qualitative – an observation that cannot be assigned a numerical value ex state (solid, liquid, gas) color, luster (shiny or dull), texture, flavor, odor Quantitative – numbers can be given Eg temperature, mass, density** Copy down table 1.1 p. 22 from textbook, understand all words

Density Density is the amount of mass for each unit of volume. Density describes how closely packed together the particles are in a material. Describe the spacing of the particles in the solid block, liquid water, and gaseous air. Most substances are denser in their solid form than in their liquid form, but water is an exception. See page 261 (c) McGraw Hill Ryerson 2007

Layers of Fluids Fluids that do not mix, layer themselves according to their density. Less dense fluids “float” on top of more dense fluids. oil Can you list the objects, in this beaker, from most dense to least dense? ball water See pages 262 - 263 (c) McGraw Hill Ryerson 2007

Fluids and Density A fluid is any form of matter that can flow. Liquids and gases are fluids since they do not have a fixed shape. Solids are not fluids. Lava, water, and syrup are examples of fluids. See page 260 (c) McGraw Hill Ryerson 2007

Measuring Density Both mass and volume are required when calculating density. Mass: Mass can be measured using a scale or balance. Volume: For objects that are block shaped, volume can be calculated by measuring the block and then using the equation: volume = length x width x height. For objects with irregular shape displacement is the method used to find the volume. balance See page 264

Density Can Change with Temperature Temperature Increase Causes thermal expansion This causes density to decrease Temperature Decrease Causes thermal contraction This causes density to increase EUREKA #19

Calculating Density Density can be calculated using the following formula: Answer the following: What is the density of a 4 cm3 rock that has a mass of 24 g? A 5 ml sample of motor oil has a mass of 4.5 g. What is the density of the motor oil? See page 265 See next slide for the answers. (c) McGraw Hill Ryerson 2007

Calculating Density Density can be calculated using the following formula: Answer the following: What is the density of a 4 cm3 rock that has a mass of 24 g? A 5 ml sample of motor oil has a mass of 4.5 g. What is the density of the motor oil? Answers 6 g/cm3 0.9 g/mL See page 265 Take the Section 7.2 Quiz (c) McGraw Hill Ryerson 2007

2. Describing Matter B. Using Classification to describe matter 1. Mixture: contains two or more substances properties of this kind of mixture varies in different samples Mechanical: particles of different substances remain clumped together (e.g. granola)

2. Describing Matter B. Using Classification to describe matter 1. Mixture: Suspensions: particles of one of the substances remain partly clumped together (e.g. tomato juice)

2. Describing Matter B. Using Classification to describe matter 1. Mixture: Solutions: particles of different substances are completely mixed together (e.g. sea water) There are more atoms in a glass of water than glass of water in all of the oceans

2. Describing Matter B. Using Classification to describe matter 2. Pure Substance: = Properties are always the same Compounds: contains two or more types of atoms joined together (e.g. salt )

2. Describing Matter B. Using Classification to describe matter 2. Pure Substance: Properties are always the same Elements: contains only one type of atom (e.g. gold)

Classification of Matter Students can work in pair to complete classifying matter worksheet or for homework

Time to meet some Elements! Meet the elements lab. Time dependent: students may work on finding symbols or looking at elements in dishes.

But not all of the elements…. Alkali metals reactivity