4 th Grade Science Unit C: Earth Sciences Chapter 6: Minerals and Rocks Lesson 1: What are minerals?

Transcription

1 4 th Grade Science Unit C: Earth Sciences Chapter 6: Minerals and Rocks Lesson 1: What are minerals?

2 mineral

3 A mineral is a natural, nonliving, solid crystal that makes up rocks.

4 All over the world, each mineral has the same chemical makeup. Scientist have identified more than 3,000 minerals. Oral Response Task Restate the definition of a mineral.

5 crystal

6 A crystal is a three-dimensional shape with flat surfaces.

7 To identify a mineral, scientists tests its properties, which include color, luster, hardness, cleavage, and crystal shape. Oral Response Task Describe a crystal.

8 luster

9 Luster is the property of a mineral that describes how it reflects light.

10 A glassy luster is shiny. A metallic luster looks like polished metal. A soft shine can be described as a waxy, silky, or pearly luster. Oral Response Task Explain the meaning of luster.

11 hardness

12 Hardness is a measure of how easily a mineral can be scratched.

13 Diamond is the hardest mineral. It has a hardness of 10. Oral Response Task Describe hardness.

14 streak

15 Streak is the color of the powder that a mineral leaves when it is scratched across a special plate.

16 Sometimes the streak is a different color than the mineral itself. For example, hematite can be silver or red but its streak is always red. Oral Response Task Evaluate why different minerals have different streaks.

17 cleavage

18 Cleavage is property of minerals that break along smooth, flat surfaces.

19 Some minerals do not have any cleavage. Quartz often breaks into pieces with smooth surfaces that look like the inside of a seashell. Oral Response Task Identify and describe the cleavage of a rock.

20 4 th Grade Science Unit C: Earth Sciences Chapter 6: Minerals and Rocks Lesson 2: How are minerals and ores sorted?

21 ore

22 Ore is a rock rich in valuable minerals that can be removed from Earth s crust.

23 Ore deposits are not common everywhere in Earth s crust. People use many different methods to find them. Oral Response Task Restate the definition of ore.

24 copper

25 Copper is a soft metal that is a good conductor and is easy to shape, often to make wire.

26 Copper is a shiny metal that is easy to shape and to make into wire and pipes. Oral Response Task Describe copper.

27 4 th Grade Science Unit C: Earth Sciences Chapter 6: Minerals and Rocks Lesson 3: How are rocks classified?

28 igneous

29 Igneous describes a type of rock that forms from molten rock.

30 Igneous rocks for from molten rocks called magma. They can form above or below earth s surface. Usually they are hard and they don t have layers but they often have crystals that interlock. Oral Response Task Explain igneous rocks.

31 lava

32 Lava is hot, molten rock that reaches Earth s surface.

33 As the lava cools, mineral crystals form. However, when lava cools quickly, there is not time for the crystals to form. Oral Response Task Describe lava.

34 magma

35 Magma is hot, molten rock that forms deep underground.

36 As magma raises slowly, it might melt some of the surrounding rock. The magma slowly cools and crystals of minerals form in the rock. Oral Response Task Distinguish between magma and lava.

37 sedimentary

38 Sedimentary describes a type of rock that forms when layers of sediments settle on top of one another and harden.

39 Sedimentary rocks are made up of soil, shells, bits of rock, and the remain of dead plant and animal matter. Oral Response Task Describe sedimentary rocks.

40 layering

41 Layering occurs when pressure on sediment that settles on top of older layers, creating newer layers.

42 Layers of rock at Earth s surface are usually younger than the layers below them. This fact helps scientists who study the ages of rocks as well as those who study things that have loved on Earth. Oral Response Task Explain the process of layering.

43 metamorphic

44 Metamorphic describes a type of rock formed when heat and pressure change the properties of rock.

45 Metamorphic rocks can form from sedimentary rocks, igneous rocks, and even other metamorphic rocks. Oral Response Task Describe metamorphic rocks.

46 4 th Grade Science Unit C: Earth Sciences Chapter 6: Minerals and Rocks Lesson 4: How do rocks change?

47 rock cycle

48 The rock cycle is the process that recycles rock into new types of rock.

49 Rocks are always changing from one form into another in a process called the rock cycle. Oral Response Task Examine the parts of the rock cycle.

50 ash

51 Ash is finely pulverized lava thrown out by a volcano in eruption.

52 Ash from volcanoes forms layers of sediment. Oral Response Task Describe ash.

53 4 th Grade Science Unit C: Earth Sciences Chapter 7: Our Changing Earth Lesson 1: How does Earth s surface slowly change?

54 landforms

55 Landforms are natural features of Earth.

56 Some landforms take shape quickly, but others take over a long time. A mountain may take millions of years to form, but rocks rolling down its side can change the mountain in a hurry. Oral Response Task List the different types of Earth s landforms.

57 weathering

58 Weathering is the process that breaks down rocks in Earth s crust into small pieces.

59 Before landforms can change, the rocks that form them must first break apart. Weathering is the process that breaks rocks in Earth s crust into small pieces. Oral Response Task Describe the process of weathering.

60 4 th Grade Science Unit C: Earth Sciences Chapter 7: Our Changing Earth Lesson 2: What causes physical weathering?

61 glaciers

62 Glaciers are huge moving sheets of ice.

63 Glaciers can cause physical weathering by creeping very slowly over land. As the glacier slides along, it drags rocks with it. Oral Response Task Restate the definition of glaciers.

64 freezing

65 Freezing is approaching, at, or below the freezing point.

66 When water freezes, it expands. Water from the rain or melted snow seeps into cracks in rocks. As the water freezes, the ice pushes against the sides of the crack. In time, the rock will split. Oral Response Task Describe freezing.

67 thawing

68 Thawing is to pass or change from a frozen state to a liquid state.

69 Cycles of freezing and thawing cause rocks to split. Oral Response Task Distinguish between thawing and freezing.

70 soil

71 Soil is the thin layer of loose, weathered material that covers most of the land surface of Earth.

72 Weathering breaks rocks into small pieces that are ingredients in soil. Oral Response Task Describe soil.

73 4 th Grade Science Unit C: Earth Sciences Chapter 7: Our Changing Earth Lesson 3: How does weathered material move?

74 erosion

75 Erosion is the movement of weathered materials.

76 Wind, water, glaciers, living things, and gravity cause erosion. Oral Response Task Illustrate the process of erosion.

77 transport

78 Transport is to carry from one place to another.

79 Water often carries, or transport, weathered materials from one place to another. Oral Response Task Analyze the effects of transport in the process of erosion.

80 gravity

81 Gravity is the force of attraction toward the center of the Earth.

82 Gravity pulls rocks and soil downhill. Oral Response Task Appraise the importance of gravity.

83 deposition

84 Deposition is the laying down of piece of rock and soil.

85 Water flowing quickly carries large particles. As the moving water slows, the large particles as well as sand are deposited at the bottom. Oral Response Task Assess the effects of deposition in the process of erosion.

86 4 th Grade Science Unit C: Earth Sciences Chapter 7: Our Changing Earth Lesson 4: What causes rapid changes to landforms?

87 landslide

88 A landslide is the rapid downhill movement of large amounts of rock and soil.

89 Landslides can cause a lot of damage. Buildings, cars, trees, and other objects are sometimes carried along with the sliding soil. Oral Response Task Describe a landslide.

90 volcano

91 A volcano is place on Earth s crust where magma reaches the surface.

92 The volcano erupts when the magma reaches the surface Oral Response Task Question the process by which a volcano erupts.

93 dormant

94 Dormant describes a volcano in a state of rest.

95 A volcano that has not erupt for a long time is said to be dormant. Oral Response Task Describe a dormant volcano.

96 active

97 Active describes a volcano that has frequent eruptions or shows signs of future eruptions.

98 An active volcano has frequent eruptions or shows signs of future eruptions. Oral Response Task Distinguish between an active volcano and a dormant volcano.

99 fault

100 A fault is a break or crack where Earth s crust can move.

101 Sometimes, rocks along a fault can get stuck. The plates however, continue their slow movement, or creep. Oral Response Task Describe a fault.

102 earthquake

103 An earthquake is a sudden movement that causes Earth s crust to shake.

104 The vibrations of an earthquake move as waves that travel through Earth. Oral Response Task Describe what happens to the Earth during an earthquake.

105 plates

106 Plates are large pieces of the Earth s crust.

107 Two plates meet along the San Andres fault. Oral Response Task Propose an explanation to the Earth s crust being broken into plates.