C13

Question 1

when was the earth formed

Answer 1

Scientists believe the Earth was formed around 4.6 billion years ago

Question 2

what gases were released from volcanoes in the early atmosphere

Answer 2

the volcanoes released CO2, H20 and N2.

Question 3

how did o2 come into the atmosphere?

Answer 3

algae photosynthesised to release O2

Question 4

when were the first simple organisms formed?

Answer 4

the first simple organisms were formed 3.4 billion years ago

Question 5

when were bacteria formed?

Answer 5

bacteria was formed 2.7 billion years ago

Question 6

why couldn’t most of the early microorganisms survive

Answer 6

due to the development of the O2 rich atmosphere

Question 7

what type of rock is coal

Answer 7

coal is a type of sedimentary rock

Question 8

how were crude oil and natural gases formed

Answer 8

they are from the remains of plankton deposited in the seabed

Question 9

why haven’t the CO2 levels changed over the last 200 million years

Answer 9

CO2 levels have not changed much due to the carbon cycle

Question 10

what are the three greenhouse gases?

Answer 10

carbon dioxide, methane, and water vapor

Question 11

how do greenhouse gases make the atmosphere hotter?

Answer 11

greenhouse gases absorb energy radiated from the earth’s atmosphere

Question 12

what do greenhouse gases do to em waves

Answer 12

greenhouse gases let short EM waves pass through, and traps long em waves

Question 13

what happens if there is a high proportion of greenhouse gases

Answer 13

the higher the proportion of greenhouse gases in the atmosphere, the more energy is absorbed

Question 14

what has burning fossil fuels to electricity caused

Answer 14

burning fossil fuels to generate electricity has increased the level of co2 in the atmosphere

Question 15

what has caused the methane levels to rise

Answer 15

swamps, rice fields, decomposing waste of cattle, and landfill sites

Question 16

how are humans affecting CO2 sinks

Answer 16

deforestation of tropical rainforests means less photosynthesis is taking place
and as temperature increases, CO2 becomes less soluble, making oceans less effective as CO2 sinks.

Question 17

how can scientists analyse the composition of the past atmosphere?

Answer 17

scientists can analyse the composition of the atmosphere from the past, by analysing ice cores drilled from Iceland’s ice sheets

Question 18

what are the consequences of global warming

Answer 18

-rising sea levels
- changes in temperature
- changes to the distribution of wildlife species

Question 19

what are wamer oceans

Answer 19

this is the ocean that has expanded because of the heat

Question 20

what is carbon footprint

Answer 20

the total amount of CO2 and other greenhouse gases released over its full life cycle

Question 21

what is capture and storage?

Answer 21

solution to reduce CO2 levels is to pump it deep underground to be absorbed into porous rocks

Question 22

how is the government dealing with global warming

Answer 22

1. taxing fossil fuels
2. taxing cars that burn lots of petrol/diesel
3. support the use of biofuels
4. there are policies that say when new trees are felled, new ones must be planted in its place.

Question 23

problems to reduce carbon footprint

Answer 23

1. lifestyle changes
2. cost
   3.people disagree that climate change has consequences

Question 24

what happens when sulfur impurities in fossil fuels are burned

Answer 24

Sulfur impurities in fossil fuels become sulfur dioxide after it’s burned

Question 24

what does sulphur dioxide cause

Answer 24

SO2 is the cause of acid rain which damages trees, kills animals and plants in lakes

Question 25

why do buildings made of limestone burn when acid rain occurs

Answer 25

acid rain also damages buildings made of limestone (limestone is calcium carbonate, which is an alkali, so when acid rain falls on it it reacts

Question 26

how do you prevent acid rain?

Answer 26

separate the sulfur impurities from the fossil fuels

Question 27

how do chimneys prevent sulfur dioxide release?

Answer 27

• SO2 is removed in waste flute where there is a layer of calcium oxide or calcium hydroxide which reacts with the SO2 therefore removing with from the gas wastes

Question 28

why is the hot temperature in an engine bad

Answer 28

high temperature inside an engine allows the normally unreactive N2 gas in the air to react with O2 making oxides of nitrogen, which are toxic and can trigger people’s asthma

Question 29

what is the equation for nitrogen?

Answer 29

4nh3 +302–> 2n2 + 6h2o

Question 30

what is the equation for methane?

Answer 30

ch4+202 –> co2+2h20

Question 31

why is nitrogen built up in the atmosphere

Answer 31

Nitrogen is added into the atmosphere by:
the reaction of ammonia with oxygen
nitrogen gas is released by denitrifying bacteria
nitrogen gas has been built up in the atmosphere as it is unreactive

Question 32

how did oxygen build up in the atmosphere

Answer 32

As the population of plants grew, the amount of O2 increased and Co2 decreased as more photosynthesis took place.
As the atmosphere became richer in O2, the animals evolved

Question 33

what 3 gases where formed by volcanic eruptions

Answer 33

they believe that early atmosphere was formed by volcanic eruptions CO2, water vapour and N2

Question 34

what did animals rely on as food

Answer 34

They couldn’t make their own food so relied on plants and oxygen to respire

Question 35

how do we know what the earth was like in the early atmosphere

Answer 35

scientists have reconstructed what the oldern atmosphere was like based on gas bubbles trapped in deep layers of ice, rock, planets and their moons

Question 36

how are fossils formed

Answer 36

some of the remains of ancient living things were crushed by large scale movements of the Earth and were heated within the crust and formed fossil fuels

Question 37

what causes global dimming

Answer 37

When the large molecules in diesel engines react with oxygen they don’t burn completely (incomplete combustion).

this produces tiny solid particles of carbon called soot. The particulates rise into the atmosphere and reflect sunlight back into space. this is called global dimming.