The earth

The earth

Learning Objectives

• Describe properties of the earth

• Describe properties of rock

• Describe properties of soil

• Describe properties of sand and clay soil

Open Ended

What is the earth made from?

The structure of the earth

Rocks, Minerals and Soils

Rock

The surface of the earth is covered by a layer of rock. This layer is called the earth's crust.

Scientists who study rocks are called "GEOLOGISTS"

Soil

Soil is made up of small particles of rocks and minerals.

Soil also contains the remains of plants, animals and waste products. All the materials that come from living things is called HUMUS.

Soils and water

Some soils allow water to pass through them very quickly. These soils drain so quickly. Other soils may hold water for a long time.

Exercise

7 Questions

Multiple Choice

This soil ingredient is made up of decayed plants

and animals.

Which of the followings belongs to definition

above?

• Air

• Humus

• Minerals

• Water

Multiple Choice

What do all rocks have in common?

• they all have minerals

• same size

• same color

• same shape

Multiple Choice

Some soils allow water to pass through them very

quickly. These soils drain quickly. Other soils

may hold water for a long time.

Which of the following type of soil dries out

quickly after a rainstorm?

• Clay

• Sand

• Silt

• Minerals

Multiple Choice

Which of the following type of soils can

become as hard as stone when it dries out?

• Clay

• Sand

• Silt

• Humus

Multiple Choice

Which of the following statements is

incorrect?

• Soil is made from rock, minerals and humus

• The particles in soil have the same sizes

• There are big spaces between the particles in

  sandy soil

• Humus is material that comes from living

  things

Multiple Choice

Which of the following minerals could NOT be

found in granite?

• Humus

• Feldspar

• Mica

• Quartz

Multiple Choice

Which of the following is NOT structure of the earth?

• Crust

• Core

• Mantle

• Soil

Learning Objectives

• Explain the formation of igneous rocks

• Describe the properties of igneous rocks

• Explain the formation of sedimentary rocks

• Describe the properties of sedimentary rocks

• Explain the formation of metamorphic rocks

• Describe the properties of metamorphic rocks

Exercise

8 questions

Multiple Choice

igneous rock formed from lava that erupted onto Earth's surface

• extrusive

• intrusive

• classic

• biogen

Multiple Choice

a sedimentary rock formed when rock fragments are squeezed together is...

• clastic

• intrusive

• chemical

• organic

Multiple Choice

a sedimentary rock formed where the remains of plants and animals are deposited in layers is

• clastic

• organic

• chemical

• extrusive

Multiple Choice

This rock was formed when molten rock cooled into a solid. What type of rock is it?

• igneous

• sedimentary

• metamorphic

• crystals

Multiple Choice

This type of rock is usually formed in layers.

• igneous rock

• sedimentary rock

• metamorphic rock

Multiple Choice

This type of rock is formed by heat and pressure.

• igneous rock

• sedimentary rock

• metamorphic rock

Multiple Choice

Most fossils are found in this type of rock.

• igneous rock

• sedimentary rock

• metamorphic rock

Multiple Choice

Marble is an example of this type of rock.

• igneous rock

• sedimentary rock

• metamorphic rock

Weathering and Fossils

Last subtopic from "the earth"

Learning objectives

• Explain how rocks change over time as a result of weathering

• Explain how rock fragments are moved

• Define fossils

• The uses of fossils

• Explain the uses of fossils record

Weathering

weathering is the wearing away of rocks by natural agents such as rain, wind, frost and temperature changes

3 types of weathering:

1. Chemical Weathering
2. Physical Weathering
3. Biotic Weathering

1. Chemical weathering

Chemical weathering is the rotting or decomposition of rocks, under the influence of atmosphere and water.

2.Physical weathering

Physical weathering is the physically wearing away of rocks due to factors like heat, water and frost. Small pieces or particles of rock prise off from the rock surface.

3.Biotic weathering

Biological weathering is a form of weathering caused by growth of roots and burrowing of animals. Plants roots are the most efficient agents of the biological weathering as they give off acids that contributes to break down of rocks.

Moving rocks

The rocks that is broken up into pieces by weathering is called "rock fragments"

Erosion

Erosion is the rock fragments that can be moved by gravity, water and wind.

Abrasion

When the fragments rub against each other the edges become smoother

Fossils

are the remains living organisms that have changed to rock.

Clues from fossils

• fossils can help us to work out how a rock formed (example: limestone contains fossils from sea plants and animals. So we know that limestone was formed under the sea)
• fossils tells us about life on earth millions years ago

Fossils record

• The fossils record tells us when different species of animals and plants first appeared on the earth
• The fossils record tells us when different species of animals and plants have changed over millions of years
• The fossils record tells us when species disappeared from the earth