1. Topic: Describing Matter Matter Describing Matter –Composition –Properties Anything that has mass and takes up space. Chemical makeup – –Water = H 2 0 –Sugar = C 6 H 12 O 6 Physical and chemical properties

2. Physical Properties –Extensive – those that change with the size of the sample –Intensive - those that remain the same regardless of the size of the sample. -A characteristic of a substance that can be observed or measured without changing the substance. -Color _________ -Shape _________ -Volume _________ -Density __________ -Texture __________ -Melting point ________ -Boiling point ________ -Generally things we can measure or see with our senses.

3. Chemical Property Chemical properties are intensive A property that describes how a substance changes into a new substance –Flammability –Reactivity Processes that involve a chemical propety Burning Rusting Rotting Baking

4. Back to Physical Properties -A characteristic of a substance that can be observed or measured without changing the substance. -color -smell -shape -volume -density -texture -melting point -boiling point

5. Density of Some Common Substances

6. Topic: Density 1. Definition of density 2. Most commonly used metric units for density The amount of mass in a given volume of a substance –Mass in grams –Volume in cm 3 g or g cm 3 ml solids liquids

8. Calculating Density To determine the density of a material you must find its volume and mass. Density = Mass ÷ Volume Here is a problem What is the density of a cube with a volume of 12cm 3 and a mass of 6.0 g?

9. Density = mass/volume Density = 6.0g /12 cm 3 Density = 0.5 g/cm 3 0.5 12 6.0 Why is the unit g/cm 3 ? Because you divided mass (g) by volume (cm 3 ) V= 12cm 3 M=6.0g