EXAM Surface of the earth

Question 1

Name the three types of rocks.

Answer 1

Igneous, sedimentary and metamorphic.

Question 2

How does igneous rock form?

Answer 2

Magma that cools slowly underground.

Question 3

Describe the 4 layers of the earth.

Answer 3

CRUST is mainly rock up to 40km and broken into plates.
MANTLE is solid and molten rock up to 2500km
OUTER CORE is liquid iron and nickel
INNER CORE is solid iron and nickel

Question 4

Describe what topsoil is.

Answer 4

The layer of soil on the surface of the earth. It is often dark in colour and contains the decomposed remains of plants and animals. This makes it rich in nutrients.

Question 5

What is subsoil?

Answer 5

The layer of soil that lies underneath the topsoil.

Question 6

How does topsoil form?

Answer 6

Topsoil forms when rocks are broken down into tiny grains over time.

Question 7

Describe the features of sandy soil.

Answer 7

Sandy soil contains more coarse sand grains and feels gritty between your fingers.

Question 8

Describe the features of clayey soil.

Answer 8

Clayey soil contains more fine grains of clay and feels smooth between your fingers.

Question 9

Describe the features of loamy soil.

Answer 9

Loamy soil is a mixture of clay and sand and contains humus. Plants grow best in loamy soil.

Question 10

Why is it useful to have small animals like earthworms and termites move through the soil?

Answer 10

They open up spaces for air and water in the soil.

Question 11

Where do nutrients come from in the soil.

Answer 11

Decomposed plants and animals.

Question 12

What does it mean when soil is eroded?

Answer 12

This is when topsoil is washed away by water or blown away by wind.

Question 13

Briefly explain what sedimentary rock is.

Answer 13

Sediment is deposited in layers and harden over many years.

Question 14

Give the 5 main stages in the formation of sedimentary rock.

Answer 14

1. Rocks break down into small grains.
2. Mud and sand grains are moved by wind and water.
3. Mud and sand are deposited in low-lying areas.
4. New layers are deposited on top.
5. The layers are compacted over time to form sedimentary rock.

Question 15

Name 3 types of sedimentary rock.

Answer 15

Shale, limestone and sandstone.

Question 16

What sedimentary rock is made from mud?

Answer 16

Shale

Question 17

What sedimentary rock is made from sand?

Answer 17

Sandstone

Question 18

What is the sedimentary rock called limestone made from?

Answer 18

The remains of dead sea animals.

Question 19

State one use of limestone.

Answer 19

To make cement.

Question 20

Describe the process of make cement.

Answer 20

Limestone is crushed and mixed with clay. The mixture is then heated to 1500 degrees celcius to make cement.

Question 21

What are shale and sandstone used for?

Answer 21

They are used to make bricks and as building blocks or tiles.

Question 22

How is metamorphic rock formed?

Answer 22

When igneous or sedimentary rock are put under high pressure and high temperature they change into metamorphic rock.

Question 23

What is the difference between the formation of granite and basalt?

Answer 23

Granite is formed when magma cools slowly inside the earth and basalt is formed when magma cools quickly on top of the earth’s surface.