Changes in Matter Physical VS Chemical Changes I8A: The student knows that changes in matter affect everyday life. The student is expected to distinguish between physical and chemical changes in matter such as oxidation, digestion, changes in states, and stages in the rock cycle. Day 2-#2

Ice cream melting is a physical change. In a physical change, the form of a substance or some of the substances properties may change, but its chemical composition – the way its atoms are put together – remains unchanged. The matter involved in a physical change keeps its identity! Physical Changes archives/2004_07.html Day 2-#2

Chemical Changes In a chemical change, the elements of one compound recombine to form one or more new chemical compounds with different properties. 2 Na + 2 H 2 O > 2 NaOH + H 2 v html To view this reaction go to: siegen.de/pci/versuche/pics/anim/natrium.mpghttp:// siegen.de/pci/versuche/pics/anim/natrium.mpg Day 2-#2

Signs of a Chemical Change: 1.Heat or light is produced. 2.Gas is produced. 3.Precipitate forms. Example of precipitate:

Verbs to help you determine a Physical VS Chemical Change: Physical: 1.Evaporate 2.Melt 3.Heat 4.Condensation 5.Cool 6.Compress 7.Subduction 8.Shattering 9.Dissolving Chemical: 1.Burning 2.Forming or Form 3.Becoming 4.Turning to 5.Rusting 6.Baking 7.Weathering 8.Combining 9.Damaging

Have a student: 1.Rip a sheet of paper 2.Grind or crush a piece of chalk 3.Place powdered chalk into a test tube and add 5% acetic acid (vinegar) 4.Dissolve salt in water 5.Light a candle

1. Identify the following as physical or chemical changes: 1.Liquid water evaporates 2.Iron rusting 3.Salt dissolves in water 4.Milk turning sour 5.Baking a cake 6.Burning wood 7.Fireworks 8.A gas condenses to become a liquid 9.Ripping a sheet of paper 10. Slicing a cake Day 2-#2

The Rock Cycle One of nature’s slowest processes – the rock cycle – is a repeating series of physical and chemical changes in which one type of rock changes to another type. Day 2-#2

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2. In the rock cycle, which of these is a chemical change involved with the formation of igneous rocks? F Compression of sediments G Heat loss from lava H Subduction of plates J Formation of minerals Question is from TEA Released TAKS Test Day 2-#2

3. Which of these changes in rocks is a physical change? A Acid rain damaging marble B Iron in rock combining with oxygen to form hematite C Carbonic acid weathering limestone D An ice wedge shattering a slab of shale Question is from TEA Released TAKS Test Day 2-#2

4. Which of the following processes is an example of a physical change associated with an oak tree? A Decomposition of bark by bracket fungi B Starches and sugars being broken down during energy production C Water and carbon dioxide being converted to glucose D Evaporation of water from the surfaces of Leaves Day 2-#2