Quarter 3 - THE PHASE CHANGES (GRADE 8).pptx

Quarter 3 - THE PHASE CHANGES (GRADE 8).pptx

1. PHASE CHANGES PREPARED BY: AIRA MAE D. DELA CRUZ -PRACTICE TEACHER-

2. Classroom Reminders Sit properly. If you want to answer, just raise your hands. Do not answer in chorus. Avoid chatting with your seatmates during class discussion. Avoid using cellphone during class discussion, unless it is needed.

3. LETS REVIEW! What are the three states of matter? How about the 4 th and 5 th state? Differentiate the particles of solid, liquid, and gas. Which among the three states of matter has definite volume?

4. WHAT HAPPENS NEXT?

5. What happens when ice is heated?

6. What happens to water during boiling?

7. What happens to clouds before rainfall?

8. What happens to bread after cutting it?

9. What happens to perfume after being sprayed?

10. What happens to dry ice after being exposed to air?

11. What happens when water form into snow?

12. Physical Change Physical changes are changes in the way matter looks. ( Grigg , 2020) Phase changes typically occur when the temperature or pressure of a system is altered. ( Helmenstine , 2019)

13. CHANGES BETWEEN A LIQUID AND A SOLID Melting This process happens when solid change directly to liquid . The solid where the molecules are in fixed positions turn into liquid where the molecules are more likely to move.

14. CHANGES BETWEEN A LIQUID AND A SOLID Melting An increase in temperature will also increase the molecular motion of the particles between the states of matter. In order for a solid to change into liquid, the object must gain thermal energy.

15. Movement of particles in Melting

16. Example:

17. CHANGES BETWEEN A LIQUID AND A SOLID Freezing It is the process occurs when liquid change directly to solid. In order for a liquid to change into solid, the object must lose thermal energy.

18. Movement of particles in Freezing

19. Example:

20. CHANGES BETWEEN A LIQUID AND A GAS Evaporation It is the process occurs when liquid change directly to gas. As evaporation takes place, the water molecules which did not escape and were left in the liquid have a lower average kinetic energy than the molecules that escaped . Evaporation is a cooling process

21. Movement of particles in Evaporation

22. Examples: Acetone Rubbing Alcohol Boiling Water Evaporation of Water

23. Condensation It is the process occurs when a gas change directly to liquid. Evaporation still happens in a covered container. Some of the molecules of water on the surface of the liquid escape and go into the gaseous state. These molecules may then collide with the inner surface of the cover and as more and more of these molecules do so, some may stay on the cover, accumulate and form droplets. This process is called condensation . CHANGES BETWEEN A LIQUID AND A GAS

24. Movement of particles in Condensation Movement of particles in Condensation

25. Examples: Moist of cold drink

26. CHANGES BETWEEN A SOLID AND A GAS Sublimation It is the process happens when solid change directly to gas. When a solid phase goes straight to a gas phase at room temperature without changing first into a liquid phase

27. Movement of particles in Sublimation

28. Examples: Dry ice Naphthalene Air fresheners

29. Deposition It is the process happens when a gas changes directly to a solid . It refers to the process in which gas changes directly to solid without going through the liquid state. CHANGES BETWEEN A SOLID AND A GAS

30. Movement of particles in Deposition

31. Examples: Ice flakes

32. THE WATER CYCLE

33. Energy Changes Accompany Phase Changes Endothermic Processes Require addition of heat to undergo phase change. Melting, Vaporization, and Sublimation Exothermic Processes Require to release heat to undergo phase change Freezing, Condensation, and Deposition

34. GENERALIZATION DEPOSITION SUBLIMATION EVAPORATION CONDENSATION MELTING FREEZING

35. Direction: Draw the resulting state of matter inside the box to complete each picture presented below and write the state of matter for each particles. Write your answers on a separate sheet of paper. Activity 2: Draw Me to Complete Me!

36. Activity 2: Draw Me to Complete Me!

37. ALWAYS REMEMBER! *DO YOUR BEST IN EVERYTHING YOU DO* *ALWAYS BE KIND TO EVERYONE*

38. I. Direction: Write FACT if the statement is correct and BLUFF if otherwise. 1. An increase in temperature will increase molecular motion between atoms and molecules in solids, liquids, and gases. 2. If a solid is being cooled, its motion of the atoms decreases. 3. Heating a gas completely stops all of its molecular motion. 4. In order for a liquid to change into solid, the object must lose thermal energy. 5. Processes in which matter changes between solid and gaseous states are melting and freezing.

39. II. Directions: Read the given sentences below and answer what is being asked. 1. It occurs when isopropyl alcohol spills over the countertop and quickly disappears. 2. It is the change in the state from gas to liquid. 3. It is a phase change that exists when a person can see his breath on a cold day. 4. It is a transition of matter from one state to another. 5. It is a process that requires the addition of heat or energy.

40. III. Directions: Choose the letter of the correct answer. 1. Which of the following is an example of a solid turning into another state of matter? a . Water freezing b . Tearing a piece of paper c . Melting of ice cube d . Breaking a chair into pieces

41. 2. What happens to water when it boils? a . It is changed into a solid b . It is changed into a liquid c . It is changed into a gas d . I t does not change at all QUESTION

42. 3. Which of the following processes requires thermal energy ? a. Condensation c . Evaporation b . Cooling d . Freezing QUESTION

43. 4. Gallium is a metal that will melt when exposed to the heat of your hand. Which phase change does Gallium undergoes? a . Gas to solid c. Solid to a gas b . Liquid to a gas d . Solid to a liquid QUESTION

44. 5. Condensation is a process where gas is changed into a liquid. Which of the following is NOT an example of condensation? a. Smoke from boiling water. b. Fog along the highway leading to Baguio. c . Water that collects outside the glass of cold drink. d. Ground-level fog that can be seen on some cold days. QUESTION

45. ALWAYS REMEMBER! *DO YOUR BEST IN EVERYTHING YOU DO* *ALWAYS BE KIND TO EVERYONE*