Using Resources

What are natural resources?

Materials supplied by Earth, sea, or air (e.g. minerals, wood, water)

What are finite resources?

Resources that will run out (non-renewable), e.g. crude oil, metals

What are renewable resources?

Resources replaced as quickly as they are used, e.g. solar, trees

What is potable water?

Water safe to drink, not pure H₂O but low in salts and microbes

What are the main methods of producing potable water in the UK?

Filtration and sterilisation of fresh water

How is water sterilised?

Chlorine, ozone, or ultraviolet (UV) light

What is desalination?

Removing salt from seawater to make it potable

What processes are used for desalination?

Distillation and reverse osmosis

What is the main disadvantage of desalination?

Requires large amounts of energy (expensive)

Why is water tested before and after treatment?

To ensure safety and quality, remove harmful substances

What is wastewater?

Used water from homes or industry

How is wastewater treated?

Screening, sedimentation, biological treatment, sterilisation

What is sewage treatment?

Removes organic matter, harmful microbes, and chemicals from wastewater

What is screening in water treatment?

Removes large solids and debris from wastewater

What is the purpose of sedimentation?

Solids settle out as sludge at the bottom

What is the role of aerobic bacteria in water treatment?

Breaks down organic material in effluent

Why do we treat sewage?

Protect health and the environment

What is sludge used for?

Can be digested anaerobically to produce biogas, used as fertiliser

What is a life cycle assessment (LCA)?

Analysis of environmental impact of a product from production to disposal

Name four stages of an LCA.

Raw material extraction, manufacturing, use, disposal

Why are LCAs useful?

Compare effects of products, highlight environmental impacts

What is a limitation of LCAs?

Some aspects are hard to quantify (subjective choices)

What is corrosion?

Destruction of materials by chemical reactions with environment

Name an example of corrosion.

Rusting of iron/steel (iron + oxygen + water)

How can rusting be prevented?

Painting, oiling, electroplating, galvanising

What is sacrificial protection?

A more reactive metal corrodes instead, e.g. zinc on steel

What is galvanising?

Coating iron with a layer of zinc to prevent rust

What is an alloy?

Mixture of a metal with other elements to improve properties

Name an alloy of copper.

Bronze (copper + tin), brass (copper + zinc)

How is steel made?

By adding carbon and other elements to iron

Why are alloys harder than pure metals?

Different sized atoms distort structure, prevent sliding

What is a ceramic?

Non-metal, inorganic solid (e.g. glass, pottery, brick)

Name a property of ceramics.

Hard, brittle, high melting points, do not conduct electricity

What is glass made from?

Melting sand (silicon dioxide) with other compounds

How is soda-lime glass made?

Melting sand, sodium carbonate, limestone

What is borosilicate glass?

Glass made with boron trioxide, more heat-resistant than soda-lime glass

What is a polymer?

Long-chain molecule made from repeating units (monomers)

How do thermosoftening polymers differ from thermosetting?

Thermosoftening can be melted and reshaped; thermosetting cannot

Name a use for ceramics.

Pottery, bricks, tiles, toilets

Why recycle metals?

Saves energy, reduces waste and mining impacts

What is the benefit of recycling glass?

Saves raw materials, energy, and reduces landfill

What is the Haber process?

Manufactures ammonia from nitrogen and hydrogen

What is ammonia used for?

Making fertilisers, explosives, cleaning products

What are the raw materials for the Haber process?

Nitrogen (air) and hydrogen (natural gas/steam)

At what temperature is the Haber process carried out?

Around 450°C

What pressure is used in Haber process?

About 200 atmospheres

What catalyst is used in Haber process?

Iron

What does NPK fertiliser stand for?

Nitrogen, Phosphorus, Potassium

What are the advantages of using NPK fertilisers?

Increased crop yield and plant health

How is phosphate rock processed for fertilisers?

Reacted with acids to form soluble phosphates

What is meant by sustainable development?

Meeting today’s needs without compromising future needs

How does recycling plastics help the environment?

Reduces resource use, landfill, pollution

Why can’t all plastics be recycled?

Some are thermosetting (cannot be remelted), others hard to sort

What is a composite material?

Material made from two or more substances to combine properties

Name a composite material.

Fibreglass, reinforced concrete, carbon fibre

Why are composites used?

Combine strength, lightness, or other properties

Why is potable water not pure?

Contains dissolved minerals and some microbes

What is reverse osmosis?

Process using membranes to filter out ions (for water desalination)

Which resource is renewable: iron, wood, oil or copper?

Wood

What is leachate?

Polluted water draining from landfills/waste

How does mining affect the environment?

Destroys habitats, pollutes waters, scars landscapes

What is phytomining?

Using plants to extract metals from soil

How does phytoextraction work?

Plants absorb metals, are burned to recover metal from ash

What is bioleaching?

Using bacteria to extract metals from ores

How does bioleaching work?

Bacteria convert minerals to soluble forms, then metals recovered

What are the benefits of bioleaching and phytoextraction?

Low energy, less pollution, uses low grade ores

What are drawbacks of bioleaching?

Slow, produces toxic leachate

What is a landfill?

Site where waste is buried

What can glass be recycled into?

New bottles, construction aggregates

How are aluminium cans recycled?

Melted and remade into new cans or products

Why is LCA important for plastics vs. paper bags?

Both have environmental costs in manufacture and disposal

What is the difference between soft and hard water?

Hard water forms lather slowly with soap, contains dissolved calcium/magnesium

What is a finite resource?

Cannot be replaced once used (non-renewable)

Why is conserving resources important?

Finite resources run out, environmental impacts

What is drinking water called in science?

Potable water

How is salt removed in distillation?

By heating to evaporate water, condensing vapour, leaving salt behind

What can sewage sludge be used for after treatment?

Biofuel or fertiliser

What is an environmental risk of untreated sewage?

Spreads disease, damages habitats, pollutes water

What role do chemists play in sustainable development?

Develop new materials, processes, recycling, reduce pollution

What is the main component of most fertilisers?

Nitrogen compounds (like ammonium nitrate)

What makes a resource "sustainable"?

It can be produced as quickly as it is used

What materials are recyclable?

Metals, glass, some plastics, paper, cardboard

How does composting help sustainability?

Returns nutrients to soil, reduces landfill

Why is copper recycled?

Copper ore limited, growing demand, energy saving

What is the purpose of water softening?

Remove calcium and magnesium ions

What are the main challenges in recycling?

Sorting, contamination, economics

What household product commonly contains ammonia?

Cleaning fluid

Why are catalysts important in industrial processes?

Speed up reactions, reduce energy costs

Give an example of "closed loop" recycling.

Aluminium cans recycled into new cans

What is the function of limestone in a blast furnace?

Removes impurities as slag

Why is steel recycled more than plastic?

Higher value, easier to sort/melt

What is the risk of excess fertiliser use?

Eutrophication, water pollution, algae blooms

How does sustainable fishing protect resources?

Allows populations to recover, long-term supply

Why are synthetic products sometimes chosen over natural?

Tailored properties, available in abundance, cheaper

What is paper made from?

Wood pulp (renewable resource)

Why is glass considered sustainable?

Recyclable many times without loss of quality

How can sustainable transport support use of resources?

Reduces fossil fuel use, adopts renewable energy, promotes recycling

Why should resources be managed globally?

Global impacts, shared supply, environmental effects

What is the major cause of ocean pollution?

Plastic waste, chemicals, oil spills

What is required before sewage is released into the environment?

Cleaning/treatment to remove harmful substances