Fire Unit Investigation I: Exploring Fire Dynamics

1. Fire Unit Investigation I: Evidence of Change Lesson 1: Fired Up Lesson 2: Hot and Cold Lesson 3: Point of View Lesson 4: Now We’re Cookin’ Lesson 5: Fat Calories Lesson 6: Burning Questions

2. Fire Unit – Investigation I Lesson 1: Fired Up

3. ChemCatalyst • Several people are left on a remote, deserted island with only the clothes on their backs. They must survive on their own. One of the first tasks they all agree on is to try and build a fire. • Why is fire so vital to their survival? • Describe a fire. • Is fire still vital to our survival? Explain. Unit V • Investigation I

4. The Big Question • What are the characteristics of fire? Unit V • Investigation I

5. You will be able to: • Describe the characteristics of fire. Unit V • Investigation I

6. Activity • Purpose: This lesson provides firsthand experience with fire. (cont.) Unit V • Investigation I

7. Unit V • Investigation I

8. Making Sense • List three characteristics of fire. Unit V • Investigation I

9. Notes • Fire: A fire is the result of a chemical change or chemical reaction. A fire releases energy in the form of light and heat. New products are formed. Smoke, ashes, or explosions can sometimes accompany fires. Unit V • Investigation I

10. Check-In • No Check-In. Unit V • Investigation I

11. Wrap-Up • A fire is the result of a chemical reaction. • A fire releases energy in the form of light and heat. • New products are formed as the result of a fire. • Chemical change and heat are associated with one another. Unit V • Investigation I

12. Fire Unit – Investigation I Lesson 2: Hot and Cold

13. ChemCatalyst • Imagine you are sitting near a campfire. You feel warm. • Explain how you think the burning wood transfers heat to your body. • The next morning you find ashes that are the same temperature as the air. Explain why the ashes are no longer hot. Unit V • Investigation I

14. The Big Question • What is the difference between “hot” and “cold?” Unit V • Investigation I

15. You will be able to: • Describe the connection between heat transfer and temperature. Unit V • Investigation I

16. Activity • Purpose: The purpose of this lesson is to give you an opportunity to track the energy exchanges that occur when matter is altered. (cont.) Unit V • Investigation I

17. (cont.) Unit V • Investigation I

18. Making Sense • What does it mean to say that something is hot? What does cold mean? Unit V • Investigation I

19. Notes (cont.) Unit V • Investigation I

20. heat transferred to the environment Notes(cont.) (cont.) Unit V • Investigation I

21. Notes(cont.) • Exothermic processes are processes in which heat is transferred to the environment. • Endothermic processes are processes in which heat is transferred from the environment. (cont.) Unit V • Investigation I

22. Notes(cont.) • Heat is the energy that is transferred from one object to another because of a temperature difference. The direction of heat transfer is always from a hotter object to a colder object. • Thermal equilibrium is reached when two or more objects in contact with one another reach the same temperature. Unit V • Investigation I

23. Check-In • You have water at 25°C. You dissolve ammonium acetate, NH4C2H4O2, in the water and find the temperature decreases to 15°C. • Is T positive or negative? • Is heat energy transferring from the solution to the environment or from the environment to the solution? • Is the process an exothermic or endothermic process? Unit V • Investigation I

24. Wrap-Up • Heat is transferred as a result of a temperature difference. • Heat is transferred from hot to cold until the objects in contact with one another are in thermal equilibrium (the same temperature). • An exothermic process is one in which heat is transferred to the environment. • An endothermic process is one in which heat is transferred from the environment. Unit V • Investigation I

25. Fire Unit – Investigation I Lesson 3: Point of View

26. ChemCatalyst • Imagine you hold a piece of melting ice in your bare hand. Use the following three words in three different sentences to describe the situation: warm, cold, heat. Unit V • Investigation I

27. The Big Question • How does point of view affect how we talk about heat transfer? Unit V • Investigation I

28. You will be able to: • Explain heat transfer from the point of view of the “system” or the “surroundings.” Unit V • Investigation I

29. Activity • Purpose: In this lesson you will consider heat transfer from different points of view. (cont.) Unit V • Investigation I

30. (cont.) (cont.) Unit V • Investigation I

31. (cont.) (cont.) Unit V • Investigation I

32. (cont.) (cont.) Unit V • Investigation I

33. (cont.) (cont.) Unit V • Investigation I

34. (cont.) Unit V • Investigation I

35. Making Sense • In any situation with a heat transfer, heat is being absorbed by something and heat is being released by something else. Explain how this applies to cooking soup over a campfire. Include a diagram. Unit V • Investigation I

36. Notes • System: The chunk of the universe being studied (i.e., a water molecule, a beaker of solution, a campfire). • Surroundings: Everything “outside” the system. (cont.) Unit V • Investigation I

37. Notes(cont.) • Heat describes the process of energy transfer. Heat is not a “thing” (a noun). • Energy is a measurement of the capacity of a system to do work or to transfer heat. • Internal energy is associated with the degree of motion of atoms. Heat transfer changes the internal energy of a system. Unit V • Investigation I

38. Check-In • Imagine a thermometer is placed in a beaker of water and the temperature is noted. An ice cube is dropped into the water and after ten minutes the temperature is noted again. • Define the system and the surroundings • What is the direction of heat transfer? Explain. • How does the internal energy of the system change? Unit V • Investigation I

39. Wrap-Up • Heat is a process of energy transfer, and in scientific thought is typically considered a verb. • A system is defined as the portion of the universe that is being focused on for purposes of tracking the movement of energy and matter. • The surrounding is that part of the universe outside of a defined system. (cont.) Unit V • Investigation I

40. (cont.) • Energy is defined as the measurement of the capacity of a system to do work or to transfer heat. • Internal energy refers to the degree of motion of the atoms in a system. • Heat transfer changes the degree of motion of the atoms, and hence the internal energy changes. Unit V • Investigation I

41. Fire Unit – Investigation I Lesson 4: Now We’re Cookin’

42. Pre-lab Quiz • How will you determine T in this experiment? • How will you determine the mass of the Cheeto that burns? • On your diagram, what is the direction of the heat transfer in this experiment? • What data will you be collecting in this experiment? • What are the two variables that are being tested in this experiment? Unit V • Investigation I

43. The Big Question • How can the transfer of heat energy be measured experimentally? Unit V • Investigation I

44. You will be able to: • Describe the direction of heat transfer between a sample of water and a Cheeto. Unit V • Investigation I

45. Notes • Calorimetry: The measurement of the amount of heat transferred. Unit V • Investigation I

46. Activity • Purpose: You will measure the amount of heat released from burning a Cheeto by measuring the temperature rise of water. You will examine four different conditions. (cont.) Unit V • Investigation I

47. (cont.) • Safety note: You will be using fire today. Make sure you wear goggles. Tie back your hair. Do not wear any loose clothing, especially loose sleeves. (cont.) Unit V • Investigation I

48. (cont.) Cheeto paperclip tuna fish can (cont.) Unit V • Investigation I

49. (cont.) (cont.) Unit V • Investigation I

50. (cont.) (cont.) Unit V • Investigation I