End of Year Review Scientific Method and Properties of Matter and Chemistry

1. End of Year ReviewScientific Method and Properties of Matter and Chemistry 8thGrade Science Curriculum

2. Essential Question #79 • How do I set up an experiment?

3. What are the potential hazards? Broken glass Spills Fire Electrical shocks Can you think of other hazards? Lab Safety

4. Essential Question #80 • How do I safely manipulate materials and equipment?

5. Lab Safety How do I safely manipulate materials and equipment and conduct appropriate procedures? • Follow safety rules covered at the beginning of the year. • Know these rules! • Follow teacher instructions. • What else applies?

6. Essential Question #80 • How do I safely manipulate materials and equipment? • Know all the safety rules of the safety contract and classroom.

7. Essential Question #81 • How do I conduct appropriate procedures?

8. Scientific Method • Ask a Question • Do Background Research • Construct a Hypothesis • Test Your Hypothesis by Doing an Experiment • Analyze Your Data and Draw a Conclusion • Communicate Your Results

9. Essential Question #81 • How do I conduct appropriate procedures? • Know and use the Scientific Method.

10. Essential Question • What types of questions can be answered through scientific investigation?

11. What types of questions can be answered through scientific investigations? How do I set up an experiment? Identify and create questions and hypotheses that can be answered through scientific investigations. Data must be measurable. Understand appropriate experimental procedures. Can you give some examples? Scientific Method

12. Essential Question #82 • What types of questions can be answered through scientific investigation? • Questions must be testable and measurable. • No opinion can be used as data.

13. How do you analyze large amounts of data? Line Graph Bar Graph Pie Chart Can you think of other ways to analyze data? Analyzing Data

14. Essential Question #83 • What are dependent and independent variables and how are they related?

15. What are dependent and independent variables and how are they related? Independent variable is the variable being tested. Can be changed to get different observations. Always the X axis Dependent variable results depend on the independent variable. Changes based on changes in the independent variable. Always the Y axis. Analyzing Data Dependent variable Independent variable

16. Essential Question #83 • What are dependent and independent variables and how are they related? • Can you explain?

17. Essential Question #84 • Why do I need a control?

18. Why do I need to have a control? Controls are not affected by the independent variable. Gives data unaffected by the variable being tested. You need to know what would happen if nothing was done to the subject being tested Scientific Method

19. Essential Question #84 • Why do I need a control? • You need to know what the results would be without the variable being tested.

20. Essential Question #85 • How many variables do I manipulate or change?

21. How many variables do I manipulate (or change)? Always Only ONE Experimentation

22. Essential Question #85 • How many variables do I manipulate or change? • Just one or you don’t know which one provided the measurable data.

23. Essential Question #79 • How do I set up an experiment? • Class discussion

24. Matter Has mass and volume Properties of Matter Mass • Amount of matter contained in a substance • Measured in grams (g) Volume • Amount of space an object occupies • Measured in liters (L)

25. Physical Change A change in a substance that doesn’t change it’s identity Example: Ice melting or chopping wood Changes in Matter Chemical Change • A change in which one or more substances combine or break apart to form new substances • Example: burning paper or putting an acid in a base

26. Essential Question #86 • How is density usedto compare different substances?

27. How is density usedto compare different substances? Density is the quantity of matter that is packed into a fixed space. D = m/v (OR) gram/liter Density = Mass/Volume Density > 1 (sinks) Density < 1 (floats) Buoyancy – the ability of a fluid to exert an upward force on an object that is immersed in the fluid Properties of Matter

28. Essential Question #86 • How is density usedto compare different substances? • Density is different for every material. If you know a materials density, it may help identify the material.

29. Essential Question #87 • How are boiling points and melting points usedto compare different substances?

30. In matter, how does temperature change? All atoms and molecules move. The faster they move, the higher the temperature Change in temperature occurs by speeding up or slowing down particle movement Properties of Matter

31. Gases Occur when particles move freely (are fluid) Volume changes by being easily compressed or expanded A gas maintains the shape of its container If these particles are heated, they move faster and need more space. This is why heat expands volume and decreases density. Created when substances boil or evaporate. If the particles slow down, they can become a liquid. (condensation) States of Matter

32. Liquids Occur when particles move freely (fluid) but are bonded to each other. Volume is constant but shape changes Movement is slower than that of gases. If these particles are heated, they easily escape and become gas. (evaporation or boiling) If they slow down, they easily get trapped in place and become a solid. (freezing) States of Matter

33. Solids Occur when particles vibrate in place Have a definite shape and volume Different substances have different freezing points. Water becomes solid at 0C if heat is taken away. This is freezing. Iron becomes solid at 1538°C if heat is taken away. This is also freezing. States of Matter

34. Of the states of matter, gas is the only state that Is fluid Has mass Is highly compressible Has a definite shape

35. Of the states of matter, gas is the only state that Is fluid Has mass Is highly compressible Has a definite shape

36. Evaporation Boiling Condensation Freezing Sublimation Liquid is changed into a vapor. Liquid is changed into a vapor by adding heat Gas cooling and becoming liquid Liquid cooling and becoming a solid Solid turning directly into a gas without becoming liquid (example: dry ice) States of MatterTerms to Remember

37. How are boiling/melting points usedto compare different substances? Different substances have different boiling/melting points. 0C is the melting and freezing point of water. 100C is the boiling point of water. Substances in water can change the boiling/melting points Properties of Matter

38. Essential Question #87 • How are boiling points and melting points usedto compare different substances? • If you can find the boiling and melting point of a substance, the information may help you identify that substance. All materials have consistent boiling and melting points.

39. Essential Question (#77) • How does water hold heat? • (We already answered, but lets review again)

40. Specific Heat The amount of energy needed to raise one gram of a substance by one degree Celsius Water has a very high specific heat This means it can absorb a lot of heat That is why water works well to put out a fire Properties of Matter

41. Essential Question (#77) • How does water hold heat? • Because of the strength of hydrogen bonds, water will hold a lot of heat. • Since there is so much water on Earth, it helps keep our climates from going to extreme temperatures.

42. Which of the following has the least effect on lake water temperature? The depth of the water The angle of incoming sun rays The number of fish in the lake The lake’s surface area

43. Which of the following has the least effect on lake water temperature? The depth of the water The angle of incoming sun rays The number of fish in the lake The lake’s surface area

44. Essential Question #88 • How is solubility used to compare different substances?

45. What is a solution? A mixture formed when one substance dissolves another. Properties of Matter What is a solvent? A substance that dissolves another substance What is a solute? A substance that is dissolved by the solvent. What is a saturated solution? Saturated: has as much solute as a solvent can hold

46. How is solubilityusedto compare different substances? Is the substance a solvent? Is the substance a solute? Does it dissolve in water? Does it dissolve in oil? What else do you know about solubility? Insoluble means that some substances are not soluble Properties of Matter

47. Essential Question #88 • How is solubility used to compare different substances? • If you find what will dissolve a substance and how fast it dissolves, it can help you identify the substance. All substances have unique dissolving qualities.

48. How can temperature affect the speed a solute will dissolve in a solvent? Remember, heat is the movement or vibration of atoms and molecules. Rapid movement of the particles of the solvent will speed up the rate of the solute breaking up (dissolving). Properties of Matter

49. Chromatography : a means of separating a mixture based on polarity and solubility Properties of Matter upload.wikimedia.org www.membrane-solutions.com Chromatography of chlorophyll Chromatography of inks

50. Essential Question #89 • How is malleability used to compare different substances?