Chapter 14 Flashcards
what are the two ways of classifying natural resources?
renewable or finite
what are finite resources?
ones that are being used up faster than they can be produced
example of finite resources 4
crude oil
limestone
metal ores
fossil fuels
what are renewable resources?
ones that are being produced at the same rate they are being used up
example of renewable resources
crops used to make biofuels
advantages of mining metal ores 3
useful products can be made
provides jobs for people
brings money into the area
main disadvantage of mining metal ores 4
uses loads of energy
scars landscape
destroys habitats
lots of waste
how are crops used in polymerisation?
ethene can be made from ethanol which can be made from fermenting sugar cane or sugar beet
what are natural resources?
ones that form without human input from earth, sea, land and air
why are renewable resources now being used?
sustainability - we must preserve the earth for future generations
what is limestone used for?
to make cement and concrete
what is the aim of the reuse, reduce, recycle campaign?
to reduce our waste, energy usage and use of limited resources
why are ceramics fit for purpose? 3
insulators of heat
brittle
stiff
why are polymers fit for purpose? 3
insulators
flexible
easily moulded
why are metals fit for purpose? 3
malleable
good conductors
ductile
what is potable water?
water that is safe to drink
what are the 3 characteristics of safe water
low levels of dissolved salts
pH between 6.5 and 8.5
no bacteria
examples of uses of water 4
drinking
solvent
coolant
washing
process of collecting water from rain?
rainwater falls to ground
collects as surface water in reservoirs or percolates through the ground into aquifers (rocks which trap water underground)
why does rainwater need to be cleaned before drinking?
it dissolves some gases in the air as it falls
when in contact with land, it will dissolve soluble materials too
what are the two ways in which water is treated and why?
filtration - to remove large solids
sterilisation - kills harmful microbes
how is water sterilised?
addition of chlorine or using ultraviolet light or ozone
when do countries need to drink salt water?
when there isn’t enough rain
how to make salt water safe to drink?
distillation
how to distil salt water
heat
the water will boil and form steam, leaving salt crystals below
the steam will condense into water in the condenser
how is reverse osmosis used to distil salty water?
the water is passed through a membrane which only allows water molecules to pass through
process of cleaning water
passes through mesh to catch large objects as it enters water treatment works
enters settlement tank - sand and soil settle out
aluminium sulfate and lime added to water
passes through fine mesh to remove any remaining particles of mud or silt
chlorine is added to sterilise
pH of water checked to ensure it is neutral
stored in tanks and distributed to consumers
process of treating sewage
- screening - passes through mesh to remove large solids
- moved to settlement tank - solid sediment is allowed to settle whilst liquid sits on top and flows into next tank
- air is pumped into the tank to encourage bacteria to break down any harmful, organic matter in it
- the useful bacteria settle as sediment, where it is removed and recycled
what is the effluent in water treatment?
the water liquid above the sludge
sources of waste water 3
the Haber process
agricultural systems
homes