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Flashcards in C2c Deck (18):

Where do we get aluminium and iron from?

-minerals we get useful materials from


How is glass made?

-limestone, sand (silicon dioxide) and soda (sodium carbonate)
-heat until it melts
-when cooled it comes out glass


How are bricks made?

-from clay (soft when dug up, so easy to mould)
-it hardens by firing at very high temperatures


How is cement made?

-clay contains aluminium and silicates
-powdered clay and limestone roasted in rotating kiln making a complex mixture of calcium and aluminium silicates (cement)


What is reinforced concrete and why is it useful?

-is a composite material
-combination of concrete and solid steel support (like steel rods)
-better for construction than ordinary concrete
-as it combines the hardness of rock with steel's flexibility and strength


What are composite materials?

-a mixture of materials


Why is extracting rocks from the environment dangerous?

-quarrying uses up land and destroys habitats (costs money to improve the look of quarry sites)
-transporting rocks causes noise and pollution
-quarrying process creates lots f dust and noise (dynamite to blast rocks out of ground)
-disused sites dangerous, turn into incredibly deep lakes
-disused mines can cause subsidence


How is pure copper obtained?

-through electrolysis
1-copper immersed in a liquid called the electrolyte which conducts electricity
-electrolyte are usually fee ions dissolved in water
2-copper (II) sulfate is the electrolyte used for purifying copper (contains Cu2+ ions)
3-pass a current through impure copper, the electrical supply acts like an electron pump:
*electrons pulled off copper atoms at the anode, causing them to go in solution as CU2+ ions
*offers electrons at the cathode to CU2+ ions to turn them back to copper atoms
*impurities dropped at the anode as sludge, while pure copper atoms bond to the cathode


What does electrolysis mean?

-splitting away with electricity
-in coppers case passing a current through impure copper splits the pure copper off from impurities


What is the cathode and its use in extracting copper?

-negative electrode
-starts as a thin piece of pure copper and more copper is added
-pure copper deposited at the pure cathode


What is the anode and its use in extracting copper?

-positive electrode
-big lump of impure copper which will dissolve
-copper dissolves from the impure anode


What is OILRIG?

-oil is loss of electrons
-reduction is gain of elections


How does recycling save money and resources?



How is concrete made and what are the benefits?

-mixing cement with sand, aggregate and water
-very quick and cheap way to construction buildings


What happens if you mix cement with water?

-slow reaction takes place and causes cement to gradually set hard


What is reduction?

-removal of oxygen


What is oxidation?

-addition of oxygen


What is subsidence?

-mines collapsing
-includes sink holes appearing buildings cracking and railway lines twisting