C1.2 Materials from the Earth

Question 1

What is magma?

Answer 1

Molten rock inside the Earth’s crust

Question 2

What is lava?

Answer 2

Molten rock on the surface of the Earth

Question 3

How are igneous rocks formed?

Answer 3

Through the solidification of magma or lava

Question 4

What does the size of crystals within an igneous rock depend on?

Answer 4

The rate at which the magma or lava cools

Question 5

When do igneous rocks form small crystals?

Answer 5

When they’re cooled quickly

Question 6

When do igneous rocks form large crystals?

Answer 6

When they’re cooled slowly

Question 7

What type of rock is granite?

Answer 7

Igneous

Question 8

What type of rock is chalk?

Answer 8

Sedimentary

Question 9

How can rocks be broken down into smaller pieces?

Answer 9

• through the expansion of water when it freezes

- erosion

Question 10

How is sedimentary rock formed?

Answer 10

• weathering of rocks creates sediment which is deposited on the bottom of lakes or seas
• layers of sediment build up over a long period of time, causing compaction
• dissolved minerals cause cementation which binds the sediment together, forming sedimentary rock

Question 11

What types of rock are marble and mylonite?

Answer 11

Metamorphic

Question 12

What are metamorphic rocks?

Answer 12

Rocks that have been changed by heat or pressure

Question 13

What type of rock is most susceptible to erosion?

Answer 13

Sedimentary

Question 14

What type of rock can have fossil remains?

Answer 14

Sedimentary

Question 15

Why are igneous and metamorphic rocks less likely to erode?

Answer 15

They have interlocking crystals which make them harder

Question 16

What are the uses of limestone as a raw material?

Answer 16

The manufacture of cement, concrete and glass

Question 17

What are the three natural forms of calcium carbonate?

Answer 17

Limestone, chalk and marble

Question 18

What are the benefits of quarrying for limestone?

Answer 18

• creates jobs in the countryside where they might be difficult to find
• improves the economy when exported to other countries

Question 19

What are the drawbacks of quarrying for limestone?

Answer 19

• dusty and noisy
• affect the quality of life of locals
• damage tourism industry
• the lorries that transport the limestone cause extra traffic, noise and pollution
• land taken up by the quarry can’t be used for other purposes like farming
• destroy the original landscape

Question 20

What does the decomposition of calcium carbonate produce?

Answer 20

Calcium oxide + carbon dioxide

Question 21

What is the thermal decomposition of limestone used to produce?

Answer 21

Cement and glass

Question 22

What is thermal decomposition?

Answer 22

The breaking down of a substance by heat

Question 23

How is cement made?

Answer 23

By heating limestone with powdered clay

Question 24

How is concrete made?

Answer 24

By mixing cement with sand, gravel and water

Question 25

How is glass made?

Answer 25

By heating limestone with sand and sodium carbonate

Question 26

What is the test for carbon dioxide?

Answer 26

Passing it through limewater and seeing if it goes milky

Question 27

What happens during a precipitation reaction?

Answer 27

Soluble substances react to form an insoluble precipitate

Question 28

What is produced from the reaction of calcium oxide and water?

Answer 28

Calcium hydroxide

Question 29

What is limewater?

Answer 29

Calcium hydroxide solution

Question 30

How do you turn calcium hydroxide into limewater?

Answer 30

You add more water until it dissolves into a solution

Question 31

What state is calcium hydroxide in?

Answer 31

Solid

Question 32

Why does carbon dioxide turn limewater milky?

Answer 32

Its reaction with limewater produces an insoluble white precipitate of calcium carbonate

Question 33

What happens to cloudy limewater when even more carbon dioxide is bubbled through it?

Answer 33

It goes back to being colourless

Question 34

Why does limewater go back to being colourless when excessive carbon dioxide is bubbled through it?

Answer 34

• the carbon dioxide reacts with water to form an acidic solution because there are no more calcium atoms to react with
• this acid neutralises the calcium carbonate so there is no longer an insoluble precipitate

Question 35

How do farmers neutralise the acidity of soil?

Answer 35

By spraying calcium carbonate, calcium oxide and calcium hydroxide on the soil to neutralise it

Question 36

What gases cause acid rain?

Answer 36

• sulphur dioxide

- nitrogen oxides

Question 37

How do power stations stop sulphur dioxide and nitrogen oxides from escaping?

Answer 37

They spray wet calcium carbonate into the chimeneys to neutralise the acidic gases