chemistry specification part 7 Flashcards
why are metals at the top of the reactivity series the most reactive?
they quickly lose their electrons to form cations. They’re also oxidised easily. Less reactive metals don’t give out cations easily and are more resistant to oxidation
what is displacement?
when a more reactive element takes place of a less reactive element
where are most metals ores extracted from?
the earths crust
where are unreactive metals extracted from and what are they called?
present in the earth’s crust, called uncombined elements
what is another meaning of oxidation and reduction?
oxidation-gaining oxygen
reduction-losing oxygen
how can metals be extracted from their ores?
-metals higher than carbon need to be extracted by electrolysis
-metals below carbon can be displaced by carbon
what is bioleaching?
uses bacteria to separate metals from their ores. The bacteria get energy from the bonds between the atoms in the ore, separating out the metal from the ore in the process. The leachate (solution produced) contains metal ions which can be extracted by electrolysis/displacement
what is phytoextraction?
growing plants in soil that contains metal compounds. The plants cannot remove the metals so they get built up in the leaves. They can be harvested, and dried in a furnace. The ash contains metal ions which can be extracted using electrolysis/displacement.
Explain the advantages of recycling metals, including economic implications.
-recycling saves money as these processes are not cheap
-recycling creates jobs,benefitting the economy
Evaluate the advantages of recycling metals, including the environment.
-mines are damaging habitats so recycling metal means we don’t need so many mines
-recycling material cuts down the amount of rubbish that gets sent to landfill which pollutes the area
