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
examples of finite resources 4
crude oil
limestone
metal ores
fossil fuels
what are renewable resources
one that are being produced at the same rate they are being used up
example of renewable resources
crops used to make biofuel
advantages of mining metal ores 3
useful products can be made
provides job for people
brings money into area
main disadvantages of mining metal ores 4
uses lots of energy
scars landscape
destroys habitats
lots waste
how are crops used in polymerisation
ethne can be made from ethanol which can be made from fermenting sugar can 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 molded
why are metals fit for purpose 3
malleable
good conductor
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 form rain
rainwater falls to ground collects as surface water in reservoirs or percolate through the ground in aquifers
why does rainwater need to be cleaned before dinking
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 is treated and why
filtration - to remove large solids
sterilisation - kill harmful microbes
how I water sterilised
addition of chlorine or using ultraviolet light or ozone
when do cpuntries need to drink salt water
when there isn’t enough rain
how to make salt water safe to drink
distillation
how to distill water
heat
the water will boil and form steam
leaving salt crystals below
the steam will condense into water in the condensing column
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 of salt
clorine is added to sterilise pH of water
checked to ensure it is neutral
stored in tanks and distributed to consumers
process of treating sewage water
screening passes through mesh to remove large solids
moved into settlement tank solid sediment is allowed to settle whilst liquid sits on the top and flows into the 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 effulent in water treatment
the water liquid above the sludge