The Earth’s atmosphere + resources

What are the three potential sources of potable water?

What are the three potential sources of potable water?

ground water, sea water and waste water

What is the proportions of the gases in Earth's atmosphere today?

78% nitrogen, 21% oxygen, 1% other (including argon - 0.9%, carbon dioxide - 0.037%)

How did the Earth's atmosphere form? (7 steps - simply)

1. Volcanoes erupted, releasing many gases

2. As the Earth cooled, water vapour (released from the volcanoes) condensed to form oceans

3. Carbon dioxide dissolved into the oceans and formed sediments

4. Algae decreases the % of carbon dioxide by photosynthesis

5. Plants evolve, increasing the % of oxygen, enabling animals to evolve

6. Sea animals used carbonates to make their shells and skeletons, forming sedimentary rocks when they died

7. Carbon dioxide became 'locked up' in fossil fuels formed by dead sea creatures and plants

For the first billion years, what gases did volcanoes erupt?

carbon dioxide, water vapour, ammonia, and methane

What are some examples of greenhouse gases?

carbon dioxide, methane, water vapour, nitrous oxide

What is the photosynthesis word equation?

carbon dioxide + water --(light)--> glucose + oxygen

What are the three ways to remove carbon dioxide from the Earth's atmosphere?

• dissolved in water (oceans)

• photosynthesis

• fossil fuels

What organism is coal formed from?

vegetation (plants)

What organism is crude oil and natural gas formed from?

sea animals

What fossil fuel began being formed first, coal or oil and gas? Why?

coal, because vegetation (plants) were alive long before animals could evolve

How has coal formed?

1. Dead plants fell into swampy water and the mud prevented them from rotting away

2. Over the years, the sediments piled up and squashed the plant remains

3. After millions of years under pressure, the mud became rock and the plants became coal

During the formation of coal, how did the dead plants not rot?

the mud prevented them from rotting away as there was no oxygen for micro-orgasnisms to use

How has crude oil and natural gas formed?

1. When tiny sea animals died, they fell into sediments such as mud and sand at the bottom of the sea, but did not rot away

2. Over millions of years, the animal remains were buried deeper by the sediments

3. The temperature and pressure changed the mud and sand into sedimentary rock, and the dead animals into crude oil and natural gas

What is a similarity of the formation of the fossil fuels? (coal and oil/gas)

any one from:

• both are created by pressure/sediments

• both are made by dead living organisms

• both began forming over millions of years ago

What is the main difference between the formation of the fossil fuels? (coal and oil/gas)

coal is made by vegetation (plants), oil and gas are made by sea animals

What is carbonate?

carbonate is a combination of carbon and oxygen that is dissolved in ocean water

What is precipitation?

any liquid or frozen water that forms in the atmosphere and falls back to the Earth

Name three natural carbon sources.

Any three from:

• forest fires

• decomposition

• volcanic eruptions

• respiration

What is a carbon source?

A source that adds carbon to the atmosphere

What is a carbon sink?

A source that removes carbon from the atmosphere

Name three anthropogenic carbon sources.

Any three from:

• burning fossil fuels

• deforestation

• landfills

• farming cattle

• quarrying

What does anthropogenic mean?

man-made/human caused

Name three natural carbon sinks.

Any three from:

• creation of fossils

• photosynthesis

• sedimentation

• oceanic storage

Name the two anthropogenic carbon sinks.

• reducing any anthropogenic carbon sources

• planting more trees

What is the percentage change formula?

final value - initial value / initial value x 100

Why is it difficult to produce models for future climate change?

because it is not that simple, and you can't predict future emissions or other human factors that influence climate change

Describe how carbon dioxide helps to maintain temperature on Earth. [3 marks]

Carbon dioxide absorbs the sunlight and traps it in the atmosphere, the sunlight transfers to heat, causing the Earth's temperature to heat up.

Increasing air temperatures can result in rising sea levels, why?

melting ice caps/sheets

What could be the effect of rising sea levels on coastal areas?

flooding of low lying areas

What is the greenhouse effect? (4 steps)

1. Energy from the sun passes through the atmosphere

2. The Earth's surface absorbs the energy and heats up

3. The Earth's surface emits infrared radiation back into the atmosphere

4. Greenhouse gases absorb some of this radiation and re-emit it back to the surface

Name three consequences of the greenhouse effect.

Any three from:

• Sea levels rise - leads to floods where you could lose land mass

• Ecosystems killed / habitats destroyed

• Harmful bacteria released that our bodies aren't immune to

• Changes to the distribution of wildlife species

• More frequent and more severe storms

• Temperature and water stress

• Changes in our ability to produce food

• Changes to timing and distribution of rainfall

What is combustion?

the burning of a fuel in air/oxygen

What happens to a fuel during combustion?

the fuel reacts with oxygen, causing the elements in the fuel to become oxidised

Name the 6 products of combustion.

• carbon dioxide (complete combustion)

• carbon monoxide (incomplete combustion)

• particulates (unburnt fuel/soot)

• water

• sulphur dioxide

• oxides of nitrogen

Name the 4 main elements in a fuel.

• carbon

• hydrogen

• sulphur

• nitrogen

What is complete combustion/when does it occur?

complete combustion happens if enough oxygen is supplied

What is incomplete combustion/when does it occur?

incomplete combustion happens if not enough oxygen is supplied

Carbon monoxide is easily identified by its strong smell. (T/F)

False, it is not able to detect with human senses

Acid rain damages buildings and statues, particularly those made from limestone. (T/F)

True

Acid rain can be prevented by spraying lakes with alkaline substances such as calcium oxide.

False, spraying lakes with alkalis treats the EFFECTS of acid rain, but doesn't prevent the acid rain happening in the first place.

What is a finite resource?

a resource that will eventually run out (opposite of infinite!)

What is a renewable resource?

a resource that will not run out because its produced as fast as its used

Name three finite resources.

any three from:

copper, aluminium, limestone, coal, iron, natural gas, clay, polythene, crude oil

Name three renewable resources.

any three from:

wood, bamboo, biodiesel, bioethanol, cotton, water

What is in distilled water? Is it safe for humans to drink?

it's almost chemically pure - most of the dissolved substances have been removed, it is safe for humans to drink but its been stripped of most of its minerals

What is in sea water? Is it safe for humans to drink?

contains lots of dissolved substances and has a very high salt content, which makes it unsafe for humans to drink (from the sea)

What is in bottled/potable water? Is it safe for humans to drink?

contains some minerals which makes it ideal and safe to drink

What is in waste water? Is it safe for humans to drink?

contains lots of bacteria and dissolved substances which makes it unsafe for humans to drink

How is waste water produced?

by human domestic and industrial activity (e.g. flushing the toilet, shower and sink drains, bathing/showering, agriculture, etc.)

What is in pure water? Is it safe for humans to drink?

contains no dissolved or undissolved substances, humans can drink it but it is unsafe to drink too much of it

What are the six simple steps of water purification?

1. Choose water source

2. Screening

3. Settlement tank

4. Filter beds of fine sand

5. Sterilise

6. Tiny amount fluoride added

During water purification, what does screening do? (step 2)

screening gets the big insoluble solids out of the water (e.g. twigs)

During water purification, what does a settlement tank do? (step 3)

settlement tanks reduce the amount of sand and soil in the water

During water purification, what do filter beds of fine sand do? (step 4)

filter beds of fine sand get all the remaining insoluble solids out of the water

During water purification, what does sterilising do? (step 5)

sterilising the water gets the microbes out (microbes make water unsafe to drink)

During water purification, what does adding a tiny amount of fluoride do? (step 6)

adding a tiny amount of fluoride to the water adds health benefits to it

If you don't have lots of rain/fresh water, but you have lots of salty water/seas or oceans. How can you get drinkable water?

By using the salty water and doing desalination

If you don't have lots of rain/fresh water, but you have lots of waste water. How can you get drinkable water?

By using the waste water and doing waste water treatment

Name one pro of desalination.

either one from:

• it can be used when freshwater supplies are scarce

• seawater is a plentiful resource if you have a coastline

Name one con of desalination.

any one from:

• roduces highly salty water which is a pollutant

• very high energy cost

• produces more greenhouse gases than other methods

• too expensive for developing countries

Name one pro of groundwater

any one from:

• low energy costs

• low greenhouse gas emissions

• plentiful resources in countries with high rainfall

Name one con of groundwater.

either one from:

• dependant on rainfall

• creating reservoirs floods large areas of land, destroying habitats

Name one pro of waste water treatment.

any one from:

• it conserves resources

• can be used when freshwater supplies are scarce

• produces biofuel as a waste product

Name one con of waste water treatment.

either one from:

• many stages in treatment

• higher energy cost than groundwater (but it is lower in energy cost than desalination)

Summarise the desalination process.

Sea water is heated until it boils. The salt remains in the liquid, and the steam is pure water. The steam is cooled and condensed to make potable water.

Name an example of a pollutant which might be present in a waste water source (human, industrial, agricultural) and why it's harmful.

any one from:

• human waste - which contains harmful bacteria and high levels of nitrogen compounds which can harm aquatic ecosystems

• industrial waste water - may contain harmful chemicals such as toxic metal compounds

• agricultural waste water - may contain fertilisers or pesticides which can disrupt sensitive ecosystems

What are the four steps of waste water treatment?

1. Screening and grit removal to remove large particles

2. Sedimentation allows tiny particles to settle out from still water, which produces sewage sludge and effluent (the liquid which remains on top)

3. The sewage sludge is digested anaerobically by specific bacteria

4. The effluent is treated with aerobic bacteria to reduce the volume of solid waste

Why do harmful bacteria need to be removed from waste water?

the harmful bacteria would be pathogens, which are harmful to humans

What are the two main step of water purification?

distillation and water analysis

What is the method of water purification by distillation? (5 steps)

1. Place salty water in a conical flask and add a few anti-bumping granules

2. Set up the apparatus for distillation

3. Heat the water using the bunsen burner until it boils gently

4. The distilled water vapour will collect in the test tube surrounded by ice and water to cool it down.

What is the method of analysing a sample of water? (7 steps)

1. Use a pH probe and universal indicator paper to measure the pH of each water sample

2. Weigh an empty evaporating basin

3. Pour the first water sample into the evaporating basin

4. Heat the evaporating basin until solids start to form and the majority of the water has evaporated

5. Leave the evaporating basin to cool completely

6. Weigh the cooled evaporating basin again

7. Repeat steps 2-7 with the other water samples

If a water sample contained a high mass of dissolved solids, what sample of water would it have most likely been?

sea water

What would be an indicator of a water sample which comes from an area which is affected by acid rain?

a low pH (between 1-7) which would show the water is acidic

Which solute is present in the highest quantity in sea water?

sodium chloride (salt)

What is the name of the process used to purify water which involves boiling the water and then cooling it to condense the vapour?

distillation

How is carbon monoxide (CO) sourced?

incomplete combustion of any fuel containing carbon atoms

How are unburned hydrocarbons sourced?

hydrocarbon fuel molecules which have not been oxidised at all

How are nitrogen oxides (NOx) sourced?

oxidation of atmospheric nitrogen inside the engine of a car, lorry, etc

What does acid rain harm?

Acid rain harms and kills plants and animals, especially those that live in aquatic environments. It can also damage man-made objects like statues and buildings.

How is photochemical smog formed?

when nitrogen oxides (from cars) react in the atmosphere with other pollutants and heat and sunlight

What are the effects of smog?

smog can have major health effects, causing asthma attacks and even death.

What is a life-cycle assessment (LCA)?

it looks at every stage of a manufactured product's life to assess the impact it has on the environment

What are the main stages analysed as part of a life-cycle assessment? (4/5 steps)

1. extracting and processing raw materials into the materials needed

2. manufacturing the product

3. using the product

4. disposing of the product at the end of its useful life

   ~ transport of the product (and raw materials) are considered at each stage

What is recycling?

converting waste into reusable material.

What are the four main stages in a recycling facility?

1. rotary screen separators (separates heavier/3D objects from lighter/2D objects like paper)

2. cross-belt magnet (separates iron-containing metals - mostly steel)

3. air classifier (separates aluminium and plastic from glass)

4. Eddy current separator (separates aluminium from plastic)

What are the steps to recycling paper? (6 steps)

1. separate different paper into bins

2. paper is compacted and baled

3. sent to a mill and placed in a hot water bath, creating pulp

4. forced through screens

5. sent to de-inker

6. clean pulp can now be recycled

What are the steps to recycling steel? (4 steps)

1. steel is crushed and baled

2. sent to foundries

3. melted down

4. mixed with new steel and refashioned (e.g. cans, beams, etc)

What are the steps to recycling glass? ( 5 steps)

1. glass goes through a rolling drum (it's shattered)

2. filtered through sieve-like screens

3. glass pieces are sorted by colour

4. crushed into tiny pieces (cullets)

5. glass is melted and reused

What are the steps to recycling aluminium? (7 steps)

1. shredded and washed

2. turned into chips

3. melted in a large furnace

4. poured into moulds

5. moulds are shipped to manufacturers

6. melted again

7. rolled into thin sheets (which can be cut, bent and shaped into new products)

What can we do to reduce the use of finite resources?

reduce, reuse, recycle (materials)!

What does biodegradable mean?

can be broken down or decomposed by microorganisms.

Why is transport considered at each stage of a life-cycle assessment?

transport uses energy and can release polluting gases into the atmosphere

Which method of disposal is likely to have the least environmental impact?

reusing

Explain why oxides of nitrogen are formed in car engines.

the high temperatures and pressures inside a car engine can cause the nitrogen and oxygen in the air to react together to make oxides of nitrogen

Explain how reducing the amount of sulphur in fossil fuels reduces the erosion of limestone. [4 marks]

Sulphur reacts with oxygen to form sulphur dioxide. If you reduce the amount of sulphur in fossil fuels, less sulphur dioxide is emitted, meaning there is less acid rain. So less limestone reacts with acid rain.

How long does it take to form fossil fuels?

millions of years

Which process removed carbon dioxide from the atmosphere?

formation of sedimentary rocks

What biochemical process absorbs carbon dioxide from the atmosphere and replaces it with oxygen?

photosynthesis

The early atmosphere contained a lot more water vapour than the modern atmosphere does. Where did it go?

it condensed to form the oceans

Which gas produced by the combustion of fossil fuels causes acid rain?

sulphur dioxide