using reasources

• what are ceramics ?

  Ceramics are non-metal solids with high melting points that are'nt made from carbon based compounds.
• what type of glass do we use ?

  soda lime
• how do you make soda lime glass ?

  heating a mixture of sand, sodium carbonate and limestone
• what are the properties of borosilicate glass

  higher BP compared to soda lime
• what is borosilicate glass made from ?

  sand and boron trioxide
• examples of clay ceramic materials

  pottery, brick, glass
• what are polymer characteristics dependant on ?

  monomers, what they are made from and the conditions they are made from eg: low and high densities
• what polymers melt when heating

  thermosoftening
• what polymers don't melt when heated ?

  thermosetting
• describe the difference in structure between thermosoftening and thermosetting polymers

  . thermosetting have covalent crosslinks linking polymer chains

  .thermosetting polymers only have weak intermolecular forces
• what are the two types of poly ethene you need to know?

  low density and high density
• what is the difference in how low and high density poly ethene is made from ethene ?

  .LDPE is made using a higher pressure and a trace of oxygen, this causes chains to form with branches, thus preventing tight packing

  .HDPE is made using a catalyst instead of oxygen and a lower temperature, this leads to no branching, allowing chains to be tightly packed
• describe LDPE

  flexible
• describe HDPE

  rigid
• what is a composite material and its structure ?

  a material made by embedding one within another, fibers surrounded by a matrix acting as a binder.
• give some examples of composite materials

  .fibreglass

  .carbon fibre

  .concrete

  .wood
• what do humans use earths resources for ?

  food, warmth, shelter and transport
• what are natural resources supplemented by ?

  agriculture
• how do natural resources form?

  without human input
• define a finite resource

  a resources that cant replenish fast enough to be consiered replaceable
• define sustainable development

  development that meets the needs of current generations without compromising the needs of future generations
• give examples of natural products supplemented by agriculture and synthetic products

  cotton - synthetic fibres such as nylon and polyester

  rubber from latex trees - synthetics

  . agriculture itself doesn't substitute for the product just aims to increase yield and availability through human interference.
• describe the properties of ceramic

  hard but brittle, porous
• describe metal as a material

  mallaeble, conductive, ductile, shiny and stiff
• describe the properties of polymers as a material

  insulators, flexible, easily moulded
• what is potable water?

  water that is safe to drink
• what is the difference between distilled water and potable water

  disstilled water is pute
• what factors need to be mitigated in potable water?

  .microbe levels

  .dissolved salts

  .undissolved material
• how is potable water made ?

  .choosing appropriate sources of fresh water eg: rivers and lakes

  .water bed filtration

  .sterilising
• what are the ways to sterilise water?

  .Ozone, chlorine, ultraviolet
• what is the fix if there is low availability of fresh water ?

  desalination
• how does desalination work

  sea water is stripped of salts by reverse osmosis, this requires huge amounts of energy
• what is the aim of waste water treatment

  . to remove any harmful microbes and organic matter or chemicals if it is industrial waste

  .this ensures it is safe to re enter the environment
• what are the waste water treatment steps?

  .screening - removes large pieces of material

  .sedimentation - separating out densities in the water, effluent to the top sludge to the bottom

  .effluent then undergoes aerobic respiration - oxygen is bubbled through the water encouraging the breakdown of organic matter and other microbes

  .sludge undergoes anaerobic respiration to break it down releasing methane used for energy.

  .sludge is then used in fertilisers and effluent is released back into the environment
• what is needed in waste water treatment if the substance contains chemical waste ?

  sterilisation or using membranes
• what is Phyto mining ?

  where plants absorb the low grade copper compounds from the soil through active transport, plants are then harvested and burned to produce ash with a higher concentration of copper. this can then be extracted using displacement or electrolysis.
• what is bioleaching ?

  bacteria produce leachate solution containing copper compounds they have extracted from the low grade ore. this can then be extracted using displacement or electrolysis.
• What is the purpose of life cycle assessments (LCAs)?

  To assess environmental impact of products
• What stages are included in a life cycle assessment?

  Extracting, manufacturing, use, and disposal
• Why is allocating numerical values to pollutant effects in LCAs challenging?

  It requires value judgments and is subjective