Physical and Chemical Properties. Book K

Transcription

1 Physical and Chemical Properties Book K

2 Warm Up: As you view the video clip, list examples of physical and chemical changes. Physical Change Chemical Change

3 Warm Up: As you view the video clip, list examples of physical and chemical changes. Physical Change Chemical Change Why are these physical changes? Why are these chemical changes?

4 Matter Anything that has mass and takes up space!

5 Matter can be described and identified by physical and chemical properties. Physical properties have to do with appearance. You can observe many physical properties with your senses and by measuring the length, width, height, mass and density of a substance.

6 Physical properties include color, shape, smell, texture, taste, and size. The state of matter (whether it s a solid, liquid or a gas) and the temperature at which the substance boils, melts, or freezes are also physical properties.

7 We can group objects by their properties. How can we group these objects?

8 1. Did you sort them by color? One property is color. Red Yellow Green Color

9 Size 2. Did you sort them by size? A second property is size. Small objects Large objects

10 3. Did you sort them by shape? A third property is shape. Squares Triangles Circles Shape

11 Chemical properties on the other hand, have more to do with the atomic or molecular composition of matter.

12 Chemical properties deal with how substances react with other substances such as air, water, or fire.

13 A chemical change has occurred when a substance has changed into something new or different so that the original substance is gone.

14 Concept of Change Change: altering or transforming from one form to another

15 How can you change your hair?

16 Concept of Change Change: altering or transforming from one form to another

17 Physical Change a change that occurs that does not alter the identity of the substance

18 Chemical Changes one or more substances are changed into new substances with new and different properties

19 Homework: Read interactive text p. 1-5 #1-16 Answer questions in the margins

20 Answers to p. 1-5 # volume: liter mass: kilogram weight: Newton 2. Amount of space an object takes up ml 4. Curved surface of a liquid in a container Volume 7. Area 8. 1 m 2

21 Answers to p. 1-5 # Put known volume of water in a g.c. add car and measure increase in water level 10. Amount of matter in an object 11. Weight 12. No, Yes 13. Kg, g, mg 14. Newton (N) 15. Resisting a change in motion 16. Higher mass, more inertia

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23 What are some physical properties of this ice cube?

24 What are some chemical properties of fireworks?

25 Concept of Change Change: altering or transforming from one form to another

26 Physical Change a change that occurs that does not alter the identity of the substance

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29 Examples: Physical Change Sand a piece of wood Sawdust is still wood!

30 Examples: Physical Change Melting Butter

31 Examples: Physical Change Dissolve Drink Mix If you heat the mixture the water evaporates and solid sugar is left

32 Examples: Physical Change Melting Ice

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34 Physical Change Why is this a physical change?

35 Chemical Changes one or more substances are changed into new substances with new and different properties A chemical change is called a chemical reaction

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39 Examples: Chemical Change Digestion of food

40 Rotting Cooking Rusting Burning

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42 Chemical Change Why is this a chemical change?

43 Evidence of a physical change: 1. Substance not changed- just size/shape Still Paper!

44 Evidence of a physical change: 2. Changing state of matter Solid Liquid

45 Evidence of a physical change: 3. Dissolving

46 Evidence of a physical change: 4. Bending, crushing, mixing

47 Evidence of a physical change: 5. Might be reversible

48 Evidence of a chemical change: 1. Color change

49 Evidence of a chemical change: 2. Gas produced: fizzing, foaming, bubbles

50 Evidence of a chemical change: 3. Heat

51 Evidence of a chemical change: 4. Sound or light produced

52 Evidence of a chemical change: 5. New substance is formed Burning a candle produces ash, carbon dioxide and water vapor

53 Is it Physical or Chemical? Change Physical Chemical Melting cheese Burning wood Milk souring Wadding up paper Bicycle rusting

54 Homework: Read interactive text p Answer questions in the margins

55 Answers to p # Can be observed/measured without making a new substance 2. Mass or weight, density, compressibility 3. Amount of matter in a given volume 4. Skip 5. Skip 6. When it is measured at the same temperature and pressure 7. Zinc 8. If it is denser than water 9. Diet soda- less dense than water

56 Answers to p # Liquid with the lowest density- corn oil 11. Affects the physical properties 12. Melting 13. Change of state 14. Change into a liquid or a solid 15. Nothing When you are done checking your answers, put your packet in the IT SECTION of your binder and take out your notes sheet. Turn to side 2 of your notes and find the THINK ABOUT IT data table.

57 Exothermic Endothermic Gives off heat- temperature increases heat energy EXITS the system surroundings usually feel warmer Ex: Monster Foam Epson salts & water Absorbs heat- temperature goes down heat energy ENTERS the system surroundings usually feel cooler Ex. Cold packs, melting ice When you pop the inner pouch, the chemical reaction absorbs heat energy from the surroundings.