C1 - topic 4 - obtaining and using metals Flashcards
1
Q
where are most ores found?
A
in the earths crust
2
Q
what metals tend to not form compounds with other elements?
A
unreative metals
3
Q
give an example of a unreactive metal that is found in combines
A
gold
4
Q
if a metal is unreative how are they found?
A
uncombined
5
Q
where can compound naturally be found?
A
in the earths crust
6
Q
if an unreactive metal is found in combined are is it extracted?
A
it is just dig up
7
Q
what is a metal ore?
A
a compound that contains enough of the metal to make it worthwhile extracting
8
Q
are there a lot of metal ores?
A
no, there is a limited amount - they’re “finite resources”
9
Q
is it harder to extract a more reactive or less reactive metal from a compound?
A
more reactive
10
Q
metals often have to be separated from their what?
A
oxides
11
Q
when metals react with oxygen what is formed?
A
oxides
12
Q
what two common metals react with oxygen to form oxides?
A
aluminium and iron
13
Q
what is the process of reaction. with oxygen called?
A
oxidation
14
Q
what are often the ores that the metals need to be extracted from?
A
oxides
15
Q
what is a reaction that separates a metal from its oxide?
A
a reduction reaction
16
Q
how is a metal ore formed?
A
the gain of oxygen - oxidation
17
Q
how is a metal extracted?
A
the loss of oxygen - reduction
18
Q
what is the most common type of reduction reaction?
A
using Carbon to separate oxygen from the metal
19
Q
most metals are found in what?
A
ores
20
Q
methods of extraction are linked to what?
A
the order of reactivity
21
Q
what is the order of reactivity?
A
potassium sodium calcium magnesium aluminium CARBON zinc iron tin lead
22
Q
what 5 metals are extracted using electrolysis?
A
potassium sodium calcium magnesium aluminium
23
Q
what 4 metals are extracted using Carbon?
A
zinc
iron
tin
lead
24
Q
what kind of metals can be extracted by heating with Carbon?
A
metals that are less reactive than Carbon - lower in the reactivity series
25
how does heating a metal with Carbon extract the metal?
Carbon reacts with the metal in the ore when heated
26
why can only less reactive than Carbon metals be extracted using Carbon?
because more reactive elements form compounds more readily
| less reactive metals allow Carbon to 'steal' oxygen from the oxide
27
Carbon can only take oxygen away from metals which are .....
less reactive than Carbon itself
28
very stable ores are creating from?
very reactive metals
29
how are metals more reactive than Carbon extracted?
by using electrolysis
30
how does electrolysis extract a metal from its ore?
it uses electricity to separate the metal from the other elements in the compound
31
when is electrolysis used to extract metals from their ores?
when metals are higher than Carbon in the reactivity series
32
what is the reactivity series?
an order of metals from most reactive to least reactive
33
how does he extraction method electrolysis work?
breaks down the ores using electricity
34
how does electrolysis remove aluminium from its ore?
1) the main ore of aluminium is bauxite, which contains aluminium oxide
2) the aluminium oxide is melted and used as the electrolyte for aluminium extraction
3) electrolysis decomposes the aluminium oxide into aluminium and oxygen atoms
4) the aluminium atoms sink the the bottom of the tank as molten a aluminium metal
35
why is electrolysis only used when metals can't be extracted using Carbon?
because it is very expensive so it is used as little as possible
36
what are the three main characteristics of metals?
strong
bendy
great conductors of both heat and electricity
37
do metals have loads of everyday uses?
yes
38
metals strength and bend ability make them useful to make what?
bridges and car bodies
39
a metal being good at conducting heat makes them useful for making what?
saucepan bases as heat can travel through it
40
what are metals used to make electrical wires?
because they're great conductors of electricity
41
do all metals have different specific properties?
yes
42
what are the properties of aluminium?
low density
| corrosion resistant
43
what is the difference between pure aluminium and an aluminium alloy?
our aluminium isn't particularly strong but it forms hard alloys which makes it very hard
44
what uses do aluminium alloys have?
window frames
electrical cables
aircraft etc
45
what are the properties of copper?
hard
strong
high melting point
good conductor of electricity
46
because of coppers properties what is it used to make?
electrical wires
pipes
plumbing
47
why can copper be used to be made into pipes and used for plumbing?
it's below hydrogen in the reactivity series, so it doesn't react with water
48
what are the properties of gold?
shiny
extremely easy to shake
unreactive
49
what is gold used for?
jewellery (easy to shape)
| to other fillings and in electric circuits (doesn't react with anything)
50
do all metals corrode the same?
no, some metals corrode more easily than others
51
why does corrosion happen?
because the metal is bit h oxidised
52
are metals that are high or low I. the reactivity series more likely to corrode?
high because they're are more likely to react with oxygen
53
is iron or lead less corrosion - resistant?
iron
54
how is rust formed in iron?
1) iron combines with oxygen ( and water)
2) the iron gains oxygen to form iron (|||) oxide
3) water then becomes loosely bonded to the iron (|||) oxide and the result is hydrated iron (|||) oxide (rust)
55
is the word 'rust' used for the corrosion of all metals?
no, just for the corrosion of iron
56
what is an alloy?
a mixture of two or more metals, or a metal and a non-metal
57
most pure iron is turned into alloys called?
steels
58
how are steels formed?
by adding small amounts of carbon and sometimes other metals to the iron
59
the alloys produced are ...... and more .....
stronger
| corrosion - resistant
60
pure iron tends to be a bit too what?
bendy
61
iron extracted using Carbon is only what percent iron?
96%
62
when iron is heated with Carbon during extraction what is the 4% that isn't iron?
impurities including Carbon
63
is impure iron brittle?
yes
64
what is brittle, impure iron used for?
ornamental railings but doesn't have many other uses
65
what kind of arrangement does pure iron have?
a regular arrangement of identical atoms
66
why is the arrangement of pure metals bad?
the atoms are all the same size (identical) so the layers of atoms can slide over eachother which makes it soft and easily shaped
67
what is a metal being too soft a problem?
it can be too bendy and soft for most uses
68
what are uses and properties of low carbon steel?
easily shaped
| car bodies
69
what the uses and properties of high carbon steel?
very hard, inflexible
blades for cutting tools
bridges
70
what are uses and properties of stainless steel?
rust - resistant
cutlery
containers for corrosive substances
71
are alloys or pure metals harder?
alloys
72
do different elements have the same or different sized atoms?
different
73
why are alloys harder than pure metals?
because when two elements combine there are bigger and smaller atoms that will upset the layers of the pure metal so it will be made more difficult for them to slide over each other
74
why are many metals in use today alloys?
because they're harder
75
what are gold alloys used to make?
jewellery
76
what metals are used to harden our gold into an alloy?
zinc
copper
Nickel
77
why isn't pure gold used to make jewellery?
because pure gold is too soft so it needs other metals to harden it
78
pure gold is described as "24 carats", so 18 carats means what?
that 18 out of 24 parts of the allot are pure gold
| 18 carat gold is 75% gold
79
what is fineness?
referring to parts of pure gold per thousand
80
alloys can be designed for specific uses because we understand what?
the properties of metals
81
what is special about smart alloys?
they return to their original shape
82
what property do most smart alloys have?
shape memory
83
what is shape memory?
when a metal remembers their original shape
84
what is an example of a smart alloy?
nitinol
85
nitinol is any alloy of what?
nickel and titanium
86
if you bend a wire made of this smart alloy, what will happen?
it'll go back to its original shape when it is heated
87
how does a smart alloy return back to its original shape?
by being heated
88
what is nitinol useful for?
glasses frames so that they can be reshape easily because of the shape memory property
89
is it important to recycle metals?
yes
90
what are 4 reasons to why recycling is useful?
it's uses less resources
it uses less energy
it uses less money
it makes less rubbish
91
why is recycling using less resources helpful?
Theres a finite amount of meta in the earth so recycling conserves them
92
why does recycling using less energy help us?
mining and extracting metals uses lots of energy which mostly comes from burning fossil fuels which we will run out of and causes pollution
93
why does recycling save money?
because energy is expensive which is needed to extract and mine metals
94
why does recycling make less rubbish?
it cuts down on the amount of rubbish that goes to landfill, which takes up space and pollutes the surroundings
95
what is the most cost - effective metal to recycle?
aluminium
96
why isn't recycling free?
because you still have to collect the waste material, transport it, sort it out, then process it
97
what would happen if you didn't recycle aluminium?
you would have to mine more aluminium which ruins the landscape (which are usually in rainforests)
the ore then needs to be transported, and the aluminium extracted
