Using resources Flashcards
What are the two types of glasses ?
What are most of the glass we use called?
What is it made out of ?
How are these two glasses different?
two different types of ceramics?
Most of the glass we use is soda-lime glass, made by heating mixture of sand, sodium carbonate and limestone.
Borosilicate glass, made from sand and boron trioxide, melts at higher
temperatures than soda-lime glass.
glass and clay
What are composite made of ?
What is the key feature ?
give some example ?
Most composites are made of two materials
reinforcement (fibres or fragments )
then reinforced by a matrix or binder material
key feature is that have different properties
eg-reinforced concrete ,fibreglass ,carbon fibre
How are clay ceramics made?
Clay ceramics, including pottery and bricks, are made by shaping wet clay and then heating in a furnace.
What is low-density polyethylene made from?
What is high-density polyethylene made from?
Low-density poly(ethene)is made from moderate temperatures under high pressure
high density -lower temperature and pressure and a catalyst
What do the properties of polymers depend on ?
The properties of polymers depend on what monomers they are made from and the conditions under which they are made.
What happens when we apply heat to thermosoftening polymers?
What happens in terms of molecules?
What happens if we cool the intermolecular forces?
Thermosoftening polymers -can be melted and reshaped,go back to solid when they cool them back down .If we heat the intermolecular forces break,each polymer strand separate from each other and the polymer melts.
If we cool the melted polymer we reform the intermolecular forces?
What happens when therometting molecules are heated ?
Thermosetting -don’t melt when we heat them
polymers are connected to each other with strong crosslinks that are not brocken by heat
What do ceramics include ?
What are the characteristics?
glass and clay ceramics
insulators of heat and electricity
brittle and stiff
Polymer characteristics?
polymers insulators of heat and electricty
mouldable
Metals
malleable, good. conductors of heat ,eelctricity ,shiny and stiff
How are alloys made ?
What metals is bronze made of ?
What metal is brass made of ?
Alloys are added by adding another element(metal),disrupting the structure of metal making them harder .
Bronze =Copper and tin -used for medals
brass =copper and zinc -water taps
aliminium alloys are used to make aircarft becasu eof its low density
What is corrosion?
What element rusts ?
What does iron need to be in contact with to rust ?
What is the equation for rust ?
corrosion-metals react with substances in environments and are gradually destroyed?
iron corrodes easily its rusts ?
iron needs to be in contact with water and oxygen to rust.
iron+oxygen+water-hydrated iron oxide (rust)
How is rust like ?
Why won’t aluminum be destroyed completely?
rust is soft and crumbly meaning eventually all the iron in an object will corrode away
aluminum won’t be destroyed completely,because aluminum oxide formed when it corrodes dosen’t flake away
Two main ways to prevent rusting?
1)coat iron with barrier to keep oxygen and water out eg-painting ,oiling and greasing
sacrificial method-involves placing a more reactive metal
such as zinc and magnesium ,water and oxygen react with sacrificial metal
Finite and renewable resources
What are natural resources?
What can natural products be replaced by ?
What can enhance natural resources ?
natural form without human input
natural products can be replaced by synthetic products .
agriculture natural resources are enhanced
What are renewable resources?
What are finite resources ?
Positives and negatives of using finite reources ?
renewable resources -reform at similar rate or faster than we use them
finite -will eventually run out arent formed quickly) enough to be replaceable (fossil fuels ,nucler fuels
extracting finite resources -useful products can be made ,provides local people with jobs .
Bad for environment ,destroys habitats
What is potable water ?
What does pure mean ?
What does Ph have to be like ?
What do we need to make sure?
safe to drink but not pure (no dissloved substances at all)
(6.5-8.5)PH -levels of dissolved salts aren’t too high
aren’t any microbes swimming around it .
contains small amount of dissolved substances
What provides most of our water ?
What type of water is it ?
Where can water be collected ?
If it is hotter water what kind of water is taken ?
In uk rainwater provides most of our potable water(its a type of fresh water )
when it rains water can either be collected as surface water(lakes ,rivers ,resevoirs) or groundwater(rocks)
surface water tends to dry up first so in hotter areas in uk groundwater is taken
What are the three steps of getting potable water ?
1)first choose a good source
2)pass water through filter beds (removing leaves and suspended particles )
3)water is sterilized killing microbes (chlorine gas )(ozone ,ultralight gas)
What happens when some areas don’t have enough groundwater or surface water ?
Two ways of achieving desalination?
some areas not have enough groundwater or surface water so need to use sea water .
Has high levels of dissolved minerals so has to go through process of desalination
1)distillation
2)reverse osmosis (water is passed through a membrane that only allows water molecules )
reduce levels of dissolved minerals
waste must be carefully treated because can pollute
1)waste is screened by going through a mesh,removes solids and grit
2)sewage settles and undergoes sedimentation,sludge sinks to the bottom whilst effluent floats at the top
3)sludge is taken away and digested by anaerobic bacteria ,this produces biogas that can be burned for electricity
What are the fours steps of sewage treatment ?
waste must be carefully treated because can pollute
1)waste is screened by going through a mesh,removes solids and grit
2)sewage settles and undergoes sedimentation,sludge sinks to the bottom whilst effluent floats at the top
3)sludge is taken away and digested by anaerobic bacteria ,this produces biogas that can be burned for electricity
4)effluent is treated by biological aerobic digestion (when air is pumped through water )
easiest way to produce potable water is through groundwater aquifiers
