C1.2

Question 1

What are igneous rocks and how are they made

Answer 1

They are rocks formed when moleten rock (lava) cools. Magma becomes lava when it erupts from the surface of the earth

Question 2

How does rate of cooling affect size of crystals in igneous rocks

Answer 2

Longer the cooling, the larger the crystals, quicker the cooling, smaller the crystals

Question 3

How is sedimentary rock formed and what is it

Answer 3

Rock made from eroded parts of other rocks of the remains of dead organisms. The eroded rock or shells build up layers in the sea. Layers build up over time and eventually the heat and pressure turns it into solid sedimentary rock

Question 4

Why does sedimentary rock erode more readily than metamorphic rock or igneous

Answer 4

It’s the only type not made of interlocking crystals so it’s a lot weaker

Question 5

What is metamorphic rock and how is it formed

Answer 5

Rocks formed when another type of rock such as sedimentary rock is put under lots of heat and pressure and forms new interlocking crystals, so it becomes stronger and a different rock. Marble is made from chalk or limestone

Question 6

Uses of limestone

Answer 6

Construction 57%
Concrete and cement 22%
Making glass or other 16%
Steel and iron alloys 5%

Question 7

How is limestone removed from the ground

Answer 7

Explosives are used to break it into smaller pieces. These are then cut or crushed into useful sizes and pieces

Question 8

Benefits of a limestone quarry

Answer 8

Lots of jobs in countryside

Good for economy

Question 9

Drawbacks of limestone quarries

Answer 9

Very loud and block small roads in the country
Ugly compared to the surrounding countryside they’re normally found in
Change natural landscape, however the owners normally restore it once the limestone is removed

Question 10

What does calcium carbonate decompose to when heated

Answer 10

Calcium carbonate —> calcium oxide + carbon dioxide

Question 11

How is cement made

Answer 11

Limestone is heated with powdered clay

Question 12

How is concrete made

Answer 12

Cement is mixed with sand, gravel and water

Question 13

How is glass made from limestone

Answer 13

Glass is made by heating the limestone with sand and sodium carbonate. This forms liquid glass which cools to make solid clear glass

Question 14

Why is zinc carbonate used in plastics

Answer 14

Helps make it more fire resistant. Heat decomposes it into zinc oxide and carbon dioxide. The zinc oxide adds a fire resistant layer and the co2 limits the o2 reaching the fire

Question 15

How is limewater made

Answer 15

Limestone is heated to make calcium oxide. Water is added to the CaO which causes a reaction and forms calcium hydroxide. More water is added to the Ca(OH)2 which dissolves it and makes limewater

Question 16

What is one use calcium carbonate, oxide and hydroxide are all used for

Answer 16

Neutralising acidic soil for farms so the crops will grow better as they are all bases

Question 17

How do coal stations stop nitrogen oxides and sulphur dioxide entering the atmosphere

Answer 17

Wet powdered calcium carbonate is sprayed through the waste gas and as they are acidic gases, the calcium carbonate reacts with them and neutralises them, reducing the harmful emissions