C1 Topic 1 & 2

Question 0

Early atmosphere made up of

Answer 0

CO2, virtually no O2

Question 1

How did levels of CO2 go down?

Answer 1

Dissolved in oceans
Photosynthesis
marine organisms, carbonate rocks

Question 2

Volcanoes in the early atmosphere did what

Answer 2

Gave out gases
CO2
water vapour - Condensed to form oceans

Question 3

Phase 3 of atmosphere

Answer 3

Oxygen killed early organisms
Complex organisms started to grow and flourished
Ozone layer (O3) blocked harmful rays from sun
Little CO2 left

Question 4

How long has the atmosphere been evolving

Answer 4

4.5 billion years

Question 5

Amount of gases in the atmosphere today

Answer 5

Nitrogen - 78%
Oxygen - 21%
CO2 - 0.04%
Other gases mostly Argon - nearly 1%

Question 6

How are we changing the atmosphere

Answer 6

Burning Fossil Fuels
Deforestation
Livestock farming - Methane

Question 7

What else changes the atmosphere

Answer 7

Volcanoes - release sulphur dioxide (which can make acid rain) & can form volcanic smog
CO2

Question 8

How can we tell the changes in the atmosphere

Answer 8

Examining bubbles in the Antarctic ice cores
Bubbles of air get trapped under the ice in layers
Examine the changes in the bubbles
Have to be very precise
Still guess work

Question 9

Test for oxygen in the air

Answer 9

Heat copper in a tube
Pass air over it using two syringes
The reaction will use up oxygen
Find how much air is left (using markers on syringe)
The air lost was used to make copper oxide so it was oxygen.

Question 10

Equation balanced for copper plus oxygen

Answer 10

2Cu + O2 –> 2CuO

Question 11

200cm3 of air , end up with 160cm3 of air

Answer 11

40cm3 or 20% is oxygen

Question 12

How are sedimentary rocks formed

Answer 12

Sediment deposited
Layers build up over millions of years
Pressure squeezes out water, crystals of different salts form.
The crystals form a sort of glue that sticks or cements the pieces of rock together.
Sedimentation –> Compaction –> Cementation

Question 13

Eg of sedimentary rocks, properties

Answer 13

Limestone, chalk. May contain fossils

Question 14

How are igneous rocks formed

Answer 14

Magma rises up into the crust or through the crust
cools and solidifies.
Extrusive –> above ground, cools quickly, small crystals
Intrusive –> underground, cooks slowly, large crystals

Question 15

Eg of igneous rocks and properties

Answer 15

Intrusive - basalt, rhyolite
Extrusive - granite, gabbro
Lots of minerals and interlocking crystals
Very very hard

Question 16

How are metamorphic rocks formed

Answer 16

Rocks subjected to heat and pressure for long periods of time.
Can cause rocks to change form/structure
If they melt they are goners :(

Question 17

Eg of metamorphic rocks and properties

Answer 17

Marble, slate
Marble is formed from chalk or limestone which has been exposed to high temps which break it down and it reforms as small crystals, giving marble an even texture and makes it harder
MM rocks are resistant to weathering because they are so hard (but not as hard as IG rocks)

Question 18

Limestone cycle 1

Answer 18

CaO3 –thermal–decomposition–> CaO + CO2

Question 19

Limestone cycle 2

Answer 19

CaO + H20 –> Ca(OH)2 (s)

Question 20

Limestone cycle 3

Answer 20

Ca(OH)2 (s) + H2O –> Ca(OH)2 (aq)

Question 21

Limestone cycle 4

Answer 21

Ca(OH)2 (aq) + CO2 –> CaCO3 + H2O

CO2 TURNS LIMEWATER CLOUDY
The cloudy bit is the calcium carbonate being made

Question 22

1calcium carbonate

Answer 22

limestone

Question 23

Uses of limestone

Answer 23

Calcium hydroxide - test for carbon dioxide.
All can be used to neutralise soil acidity.
Calcium carbonate - remove acidic gases from coal-powered power station chimneys

Question 24

Limestone as a building material

Answer 24

Blocks of limestone are good for building with but it wears away with acid rain because it reacts with the CO2 in the water Heated with clay in a kiln to make cement Cement mixed with sand water and gravel to make concrete Heated with sand and sodium carbonate to make glass

Question 25

Problems with concrete, limestone and glass

Answer 25

Concrete is weak when squashed, steel can be added, it is ugly Limestone wears away in acid rain Glass is brittle and shatters easily, but can be toughened. Glass can make buildings too hot

Question 26

Advantages of limestone quarrying

Answer 26

Makes jobs houses and roads More money in the local economy, local improvements like transport health etc restoration of landscape is part of the plan

Question 27

Disadvantages of limestone quarrying

Answer 27

``` Makes noise and dust Destroys habitats Ugly view, holes change landscape Transporting makes noise and pollution Waste materials go into tips ```

Question 28

What is a precipitation reaction

Answer 28

Two solutions react and an insoluble solid forms | The solid is called a precipitate

Question 29

Balance copper sulphate + sodium hydroxide

Answer 29

copper sulphate + sodium hydroxide --> copper hydroxide (precipitate) + sodium sulphate (solution) CuSO4 + NaOH --> Cu(OH)2 + Na2SO4 CuSO4 + 2NaOH --> Cu(OH)2 + Na2SO4

Question 30

2 calcium oxide

Answer 30

Quicklime

Question 31

3 calcium hydroxide (s)

Answer 31

Slaked lime

Question 32

4 calcium hydroxide (aq)

Answer 32

Limewater

Question 33

Limestone

Answer 33

Calcium carbonate Thermal decomposition

Question 34

Quick lime

Answer 34

Calcium oxide +water

Question 35

Slaked lime

Answer 35

Calcium hydroxide (s) +water

Question 36

Limewater

Answer 36

Calcium hydroxide (aq) +co2