Weather Unit

1. Weather Unit Investigation I: Locating Matter Lesson 1: Weather or Not Lesson 2: Raindrops Keep Falling . . . Lesson 3: Having a Melt Down Lesson 4: It’s Sublime Lesson 5: Water World

2. Weather Unit – Investigation I Lesson 1: Weather or Not

3. ChemCatalyst • Below are a picture and weather report of a hurricane off the coast of Florida in the United States. (cont.) Unit 3 • Investigation I

4. (cont.) • FORECAST FOR THE MIAMI AREA: The tenth depression of the season in the Atlantic has become Hurricane Jan. The center of Jan is southeast of Florida. The maximum sustained winds are near 120 miles per hour. The estimated minimum central pressure is 28.5 inches. Skies over Miami are mostly cloudy. The temperature is 35C / 95F with 90% humidity. (cont.) Unit 3 • Investigation I

5. (cont.) • Jan is expected to drop as much as 10 inches of rain in the southern part of Florida with rising temperature and humidity. • What are hurricanes and what do you think causes them? • What is weather? What causes weather? • How do meteorologists predict things like hurricanes? Unit 3 • Investigation I

6. The Big Question • What causes water to ‘cycle’ or move around on the planet? Unit 3 • Investigation I

7. You will be able to: • Explain what causes rain on the planet Earth. Unit 3 • Investigation I

8. Activity • Purpose: In this activity you will heat and cool water in a flask with a balloon attached. Your observations will help you determine what makes the water “cycle.” (cont.) Unit 3 • Investigation I

9. (cont.) Materials: (for each team of two students) 250 mL Erlenmeyer flask 25 mL graduated cylinder Medium sized party balloon 5 mL of water Hot plate Oven mitt Bucket or large beaker with ice and water Unit 3 • Investigation I

10. Making Sense • Based on this experiment, explain what causes water to “cycle” around the planet? Unit 3 • Investigation I

11. Notes • Evaporation is the changing of a substance from the liquid phase to the gas phase. Condensation is the changing of a substance from the gas phase to the liquid phase. • Gas, liquid, and solid are three different phases of matter. A phase change refers to the conversion of a liquid to a gas or a solid, or vice versa. • A physical change is one in which the form or temperature of a substance is changed without changing its chemical make-up. (cont.) Unit 3 • Investigation I

12. Notes(cont.) • Humidity is a measure of the amount of water vapor (or gaseous water) in the air. Unit 3 • Investigation I

13. Check-In • Answer the following question: • Using what you learned today about the movement of water, explain what causes rain on the planet Earth. Unit 3 • Investigation I

14. Wrap-Up • Weather is an interaction between the sun (a heat source), the water on the planet, the Earth’s surface, and the Earth’s atmosphere. • Water moves around through phase changes. • Phase changes affect the volume of substances. Unit 3 • Investigation I

15. Weather Unit – Investigation I Lesson 2: Raindrops Keep Falling . . .

16. ChemCatalyst • Annual rainfall in the United States (cont.) Unit 3 • Investigation I

17. (cont.) • How much rain fell where you live? • How is rainfall measured? • What type of instrument or container is used to measure rainfall? Unit 3 • Investigation I

18. The Big Question • How do meteorologists keep track of rainfall? Unit 3 • Investigation I

19. You will be able to: • Relate volume of water to rainfall amount. Unit 3 • Investigation I

20. Activity • Purpose: This lesson introduces you to precision in measurement and allows you to explore measuring rainfall in inches and milliliters. (cont.) Unit 3 • Investigation I

21. (cont.) • Materials: (per team of 2 students) • 25 mL graduated cylinder • 100 mL beaker • 12 inch ruler • Water bottles (use plastic pipettes or droppers if you do not have water bottles) Unit 3 • Investigation I

22. Making Sense • Meteorologists can keep track of the amount of rainfall by measuring either the volume or the height of rainfall in a rain gauge. • If the amount of rainfall increases, do both the volume and height of water in the rain gauge keep track of this increase? Explain your thinking. (cont.) Unit 3 • Investigation I

23. (cont.) • What does the precision of measuring height and volume depend on? Is there a difference in the precision of measuring height or volume? Explain your thinking. (cont.) Unit 3 • Investigation I

24. (cont.) Unit 3 • Investigation I

25. 55 50 Notes • Significant figures are the numbers one can read off of an instrument or piece of equipment,plus one more estimated number. The glassware or instrument being used in a measurement determines how many significant figures can be recorded. (cont.) Unit 3 • Investigation I

26. Notes (cont.) Significant Figures (cont.) Unit 3 • Investigation I

27. Measuring Rainfall Data Notes(cont.) (cont.) Unit 3 • Investigation I

28. Notes(cont.) • Two quantities are proportional if a graph of the two variables results in a straight line that passes through the origin (0, 0). (cont.) Unit 3 • Investigation I

29. 0 1/2 1 1 1/2 2 2 1/2 3 3 1/2 4 Notes(cont.) Unit 3 • Investigation I

30. Check-In • Answer the following question: • Suppose you find that 1.0 inch of rainfall in a graduated cylinder has a volume of 4.0 mL. What volume would you measure for 2.0 inches of rainfall? • A) 4 mL B) 4.0 mL C) 4.00 mL D) 8 mL E) 8.0 mL F) 8.00 mL • Explain your thinking. Unit 3 • Investigation I

31. Wrap-Up • Precision differences in measurements are a result of the glassware or instrument that is used. • Significant figures are defined as all of the numbers that can be read directly from an instrument, plus one estimated number. (cont.) Unit 3 • Investigation I

32. (cont.) • The volume of water in a cylindrical container is directly proportional to the height of the water. • Graphs of two variables that are proportional always lead to a straight line through the origin. Unit 3 • Investigation I

33. Weather Unit – Investigation I Lesson 3: Having a Melt Down

34. ChemCatalyst • Meteorologists measure the snowpack in the mountains to predict the amount of water that will fill the lakes and reservoirs. Do you think that 3 milliliters of snow is the same as 3 milliliters of rain? Explain your reasoning. Unit 3 • Investigation I

35. The Big Question • How can you convert from volume of snowfall to volume of liquid water? Unit 3 • Investigation I

36. You will be able to: • Understand the relationship between density, mass and volume. Unit 3 • Investigation I

37. Notes • The density of a substance is the slope of the line for a graph of mass vs. volume. • Density = Mass/Volume (cont.) Unit 3 • Investigation I

38. Notes(cont.) • The slope of a line is the change in y divided by the change in x. • For a line that goes through the origin (0, 0), the slope is simply any value of y divided by the corresponding value of x. (cont.) Unit 3 • Investigation I

39. Slope = Density Notes(cont.) Unit 3 • Investigation I

40. Activity • Purpose: This activity allows you to relate volume of snowfall with volume of rainfall by using the density of snowfall and rainfall. (cont.) Unit 3 • Investigation I

41. (cont.) • Materials: (for each team of four students) • 25 mL graduated cylinder • Scale • Water bottle (small dropper or plastic pipette if water bottles are not available) (cont.) Unit 3 • Investigation I

42. (cont.) Mass of the graduated cylinder empty: ______ Unit 3 • Investigation I

43. Making Sense • Explain how you can relate volume of snow to volume of rain. (cont.) Unit 3 • Investigation I

44. water ice snow (cont.) (cont.) Unit 3 • Investigation I

45. (cont.) • m1 / V1 = slope = m2 / V2 (cont.) Unit 3 • Investigation I

46. (cont.) • Example Problem I: • Imagine you have a box that is 5.0 mL in volume. What mass of ice will just fit this box? (cont.) Unit 3 • Investigation I

47. (cont.) • Example Problem II: • You have 20 grams of snow with a density of 0.50 g/mL. What volume does this snow occupy (how many milliliters)? Unit 3 • Investigation I

48. (cont.) • Example Problem III: • If you have 100 mL of snow, what volume of water do you have? (You must first find out what mass of snow you have and then convert that to volume of water.) (cont.) Unit 3 • Investigation I

49. (cont.) Unit 3 • Investigation I

50. (cont.) Unit 3 • Investigation I