2. The Water Cycle

3. evaporation

4. The Water Cycle evaporation condensation

5. The Water Cycle evaporation precipitation condensation

6. The Water Cycle Snowflakes form at the condensation stage.

7. The Water Cycle Snowflakes form at the condensation stage. The water vapor condenses directly into ice!

8. The Water Cycle Snowflakes form at the condensation stage. The water vapor condenses directly into ice! This process is called “sublimation.”

9. Why?

11. temperature

12. Temperature: the measurement of how hot or cold something is.

13. humidity

14. Humidity: the amount of water vapor in the air.

18. A snowflake is made of ice crystals.

19. A snowflake is tiny. A snowflake is made of ice crystals.

20. A snowflake is tiny. A snowflake is made of ice crystals.

21. A snowflake is symmetrical. A snowflake is tiny. A snowflake is made of ice crystals.

22. Symmetry – Two Dimensional Polygons Key words:

23. Symmetry – Two Dimensional Polygons Key words: A regular polygon is a polygon in which all sides are the same length.

24. Symmetry – Two Dimensional Polygons Key words: A regular polygon is a polygon in which all sides are the same length. A line of symmetry for a polygon is any line on which the polygon can be folded so that one half of the polygon will fall exactly on the other half.

26. Number of Sides of Regular Polygon Name of Regular Polygon Number of Lines of Symmetry 3 4 5 6

27. Number of Sides of Regular Polygon Name of Regular Polygon Number of Lines of Symmetry 3triangle 4 5 6

28. Number of Sides of Regular Polygon Name of Regular Polygon Number of Lines of Symmetry 3triangle3 4 5 6

29. Number of Sides of Regular Polygon Name of Regular Polygon Number of Lines of Symmetry 3triangle3 4square 5 6

30. Number of Sides of Regular Polygon Name of Regular Polygon Number of Lines of Symmetry 3triangle3 4square4 5 6

31. Number of Sides of Regular Polygon Name of Regular Polygon Number of Lines of Symmetry 3triangle3 4square4 5pentagon 6

32. Number of Sides of Regular Polygon Name of Regular Polygon Number of Lines of Symmetry 3triangle3 4square4 5pentagon5 6

33. Number of Sides of Regular Polygon Name of Regular Polygon Number of Lines of Symmetry 3triangle3 4square4 5pentagon5 6hexagon

34. Number of Sides of Regular Polygon Name of Regular Polygon Number of Lines of Symmetry 3triangle3 4square4 5pentagon5 6hexagon6

35. How many lines of symmetry does Snowflake 1 have? __________ How many lines of symmetry does Snowflake 2 have? __________ What regular polygons are these snowflakes? __________________

36. A snowflake is symmetrical. A snowflake is tiny. A snowflake is made of ice crystals.

37. A snowflake is 3 dimensional. A snowflake is symmetrical. A snowflake is tiny. A snowflake is made of ice crystals.

38. 2-Dimensional & 3-Dimensional Objects

39. Circle

40. 2-Dimensional & 3-Dimensional Objects CircleSphere

41. 2-Dimensional & 3-Dimensional Objects Square

42. 2-Dimensional & 3-Dimensional Objects SquareCube

43. 2-Dimensional & 3-Dimensional Objects Triangle

44. 2-Dimensional & 3-Dimensional Objects TriangleTriangular Prism

45. 2-Dimensional & 3-Dimensional Objects Rectangle

46. 2-Dimensional & 3-Dimensional Objects RectangleRectangular Prism

47. 2-Dimensional & 3-Dimensional Objects Hexagon

48. 2-Dimensional & 3-Dimensional Objects HexagonHexagonal Prism

50. Why?

51. 1 oxygen atom 2 hydrogen atoms

55. Do you see the similarities in shape? Crystal lattice formed by frozen water molecules Snowflake

56. Do you see the similarities in shape? Crystal lattice formed by frozen water molecules Snowflake

57. Self–assembly:

58. Self–assembly: a process by which materials build themselves without assistance.

59. Snowflakes self-assemble… they build themselves!

60. How does a snowflake grow?

61. Initial formation of a snow crystal around a dust particle in the cloud.

62. How does a snowflake grow? Initial formation of a snow crystal around a dust particle in the cloud. Crystal grows into a hexagonal prism.

64. How does a snowflake grow? Initial formation of a snow crystal around a dust particle in the cloud. Crystal grows into a hexagonal prism. Crystal grows larger – corners may sprout “arms.”

66. How does a snowflake grow? Initial formation of a snow crystal around a dust particle in the cloud. Crystal grows into a hexagonal prism. Crystal grows larger – corners may sprout “arms.” Crystal moves to different temperatures and different levels of humidity – plates may grow arms.

68. How does a snowflake grow? Initial formation of a snow crystal around a dust particle in the cloud. Crystal grows into a hexagonal prism. Crystal grows larger – corners may sprout “arms.” Crystal moves to different temperatures and different levels of humidity – plates may grow arms. Crystal moves through many different temperatures and different levels of humidity – each change may cause new growth in arms.

70. How does a snowflake grow? Initial formation of a snow crystal around a dust particle in the cloud. Crystal grows into a hexagonal prism. Crystal grows larger – corners may sprout “arms.” Crystal moves to different temperatures and different levels of humidity – plates may grow arms. Crystal moves through many different temperatures and different levels of humidity – each change may cause new growth in arms.

73. Natural Snow Artificial Snow

74. Ice

75. Natural Snow Artificial Snow IceChemical polymer

76. Natural Snow Artificial Snow Ice Melts above 32F Chemical polymer

77. Natural Snow Artificial Snow Ice Melts at 32F Chemical polymer Does not melt at 32F

78. Natural Snow Artificial Snow Ice Melts at 32F Edible Chemical polymer Does not melt at 32F

79. Natural Snow Artificial Snow Ice Melts at 32F Edible Chemical polymer Does not melt at 32F Inedible

80. Natural Snow Artificial Snow Ice Melts above 32F Edible Hexagonal prisms Chemical polymer Does not melt Inedible

81. Natural Snow Artificial Snow Ice Melts at 32F Edible Hexagonal prisms Chemical polymer Does not melt at 32F Inedible No hexagonal prisms

82. Artificial Snow (magnified 10 times) Image of magnified artificial snow.

83. Artificial Snow (magnified 60 times) Image of magnified artificial snow.

84. Natural Snow (magnified 10 times) Need to find a magnified image of natural snow.

86. All snowflake images courtesy of www.snowcrystals.com

87. 8.5” x 8.5” Paper Scissors Standard Ruler Pencil

88. 1.

89. 2.

90. 3.

91. 4.

92. 5.

93. 6.