Uses of metals and alloys (44, 45, 21) (paper 1) Flashcards
what are most metals found in
ores
how are unreactive metals found like gold and silver
they are uncombined
what is a metal ore
a compound which contains enough of the metal to make it worthwhile extracting
are there unlimited amounts of metal ores
no they’re finite resources
is it easier or harder to extract a very reactive metal from its compound
it is harder to extract a more reactive metal from a compound
what type of ores are found in common metals and how are they found
common metals like iron and aluminium are found in metal oxide ores
how can metals be seperated from metal oxide ores
by a reduction reaction
what happens in the most common type of reduction reaction
using carbon as a reduction agent to seperate the oxygen from the metal
why do different metals require different extraction methods
because some metals are more reactive than others
do very reactive metals form very stable ores
yes
what method of extraction is used to seperate out metals more reactive than carbon from its ore
electrolosis
what is electrolosis
it uses electricity to seperate the metal from the other elements in the compound
what metals are used most
- iron
- aluminium
- copper
what are the beneficial properties of iron, aluminium and copper
- dense and shiny
- have high melting points
- hgih tensile strength
- malleable
- good conductors of electricity and heat
what does the uses of iron, aluminum and copper depend on
their properties
what are the uses of iron
wrought iron is used to make gates and railings although it rusts
what are the uses of aluminium
- cans for drinks = doesn’t corrode when with water
- meterials for bike frames and aeroplanes = light metal
what are the uses of copper
- wiring = low resistance and good conductor
- heating systems = good conductor
how can metals be made stronger
by making them an alloy
why are alloys stronger than pure metals
- different elements have different shaped atoms
- new atoms distort the layers of metal atoms
- making them more difficult to slide
- = they are harder
what are alloys of iron called
steels
how are steels made
by adding small amounts of carbon and sometime other metals
what is brass formed from
copper and zinc
what is bronze formed from
copper and tin
what are the 3 different types of steel
- low carbon steel = malleable = cars
- high carbon steel = very strong = bridges
- stainless steel = corrosion-resisatnt, hard = cuttlery
what is electric current
the flow of electrons or irons
what happens when electrons or irons move
they cause the material to conduct electricity
when do ionic compounds conduct electricity
when molton or in a solution
why dont ionic compounds conduct when solid
because the ions cannot move
what is the structure of metals
giant structures of positive ions surrounded by a sea of delocalised electrons
what is metalic bonding
the electrostatic attractions between the nuclei of the positive ions and electrons
why are metals malleable
because the layers of ions in a metal can slide over each other
