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Appetizer – 1/13/13. Which of the following is an example of a physical change? Burning methane gas produces water and carbon dioxide Vinegar and baking soda combine to form a salt and water Condensation of water vapor on the outside of a cold can of soda
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Appetizer – 1/13/13 Which of the following is an example of a physical change? • Burning methane gas produces water and carbon dioxide • Vinegar and baking soda combine to form a salt and water • Condensation of water vapor on the outside of a cold can of soda • Formation of silver sulfide when silver reacts with sulfur in the air
Chapter 15 The Classification of Matter
Section 1: The Composition of Matter Matter – What is it? • Has mass and takes up space • Is made of atoms • Is defined by what it’s made of and how it interacts with other types of matter
What is Matter? Matter Not Matter Heat Light sound • Living things • Non living things • Air • The earth
Pure Substances • Pure substances have a fixed composition meaning that any sample of the substance is always made of the same thing • Examples: Water, Salt, gold, graphite (pencil lead), oxygen
Elements • A pure substance that is made of atoms which are all identical • About 90 elements are found on earth • Examples: iron (Fe), helium (He), oxygen (O) , copper (Cu), gold (Au), aluminum (Al),
Compounds • Two or more atoms combine in fixed ratios to form compounds • Examples: water (H2O), carbon dioxide (CO2), salt (NaCl) + =
Mixtures • Two or more substances that can be separated with physical processes • Do not always contain the same types of ingredients in the same proportions • Example: pizza
Section 2: Properties of Matter Physical Properties – any characteristic of matter that you can observe without changing the identity of the substances that make up the material • Examples: color, shape, appearance, texture, size, melting point, boiling point, density
Physical Properties • Appearance and behavior • Examine the playdoh with a partner. Write down all of the physical properties of the playdoh that you can find
Physical Properties • Mixtures can be separated based on physical properties of the substances • Examples: pouring pasta and water into a strainer, separate iron filings from sand with a magnet, filtering water
Physical Change • Freezing- liquid solid : water ice • Boiling - liquid gas : water steam • Evaporation - liquid gas : water water vapor • Melting - solid liquid : ice water • Condensing - gas liquid : water vapor drops
Because all substances have distinct properties like densities, specific heats, melting, and boiling point, these properties can be used to help identify when a mixture contains a particular substance
Using physical change to separate • Distillation is a process where a mixture is separated by heating the mixture and condensing the liquid that evaporates. • Used to make drinking water out of sea water when fresh water is not available
Chemical Changes • New substances are produced when a chemical change occurs • Heat, cooling, formation of bubbles, and color change can all indicate a chemical change • Examples: rust on a car fender, baking cookies, mixing baking soda and vinegar
Review • This assignment must be completed for homework if you do not finish by the end of class! • Page 470 # 1-7 (fill in the blank. Just write the word) • Page 471 # 19 (use the concept map print-out)