Metals

Question 1

what are properties of metals?

Answer 1

• malleable
• ductile
• high density
• high MP BP
• good conductors of heat and electricity

Question 2

what does malleable mean?

Answer 2

can be easily beaten into fine wires without breaking

Question 3

what does ductile mean?

Answer 3

can be stretched into fine wires without breaking

Question 4

why are metals malleable and ductile?

Answer 4

their atoms are of the same size and are arranged in orderly layers. so layers can slide over each other easily when a force is applied

Question 5

why do metals have high density?

Answer 5

as their metal atoms are closely packed together

Question 6

why do metals have high melting and boiling points?

Answer 6

as their metal atoms are packed tightly in layers by strong metallic bonds. a lot of energy is needed to break the strong metallic bonds

Question 7

why are metals good conductors of heat and electricity?

Answer 7

as they have a sea of delocalised mobile electrons that can carry charges

Question 8

what are alloys?

Answer 8

a mixture of metals with one or more elements

Question 9

what is bronze made of?

Answer 9

copper and tin

Question 10

what is steel made of?

Answer 10

iron and carbon

Question 11

what is steel used for?

Answer 11

car bodies and machinery

Question 12

what is stainless steel made of?

Answer 12

iron, carbon and small amounts of chromium and nickel

Question 13

what is stainless steel used for?

Answer 13

cutlery, utensils and surgical instruments

Question 14

what is brass made of?

Answer 14

copper and zinc

Question 15

what is brass used for?

Answer 15

coins and musical instruments

Question 16

what is the structure of metals?

Answer 16

• pure metals are weak and soft
• atoms of the same size and are arranged in regular layers which slide over easily when force is applied
• soft and malleable

Question 17

what is the structure of alloys?

Answer 17

• hard and strong
• different sizes of atoms disrupt regular and orderly arrangements of atoms
• difficult for atoms in an alloy to slide over each other when force is applied
• stronger and less malleable than pure metals

Question 18

what is the product of the reaction between metal and water?

Answer 18

metal hydroxide and hydrogen

Question 19

what is the product of the reaction between metal and steam?

Answer 19

metal oxide and hydrogen

Question 20

what is the product of the reaction between metal and acids?

Answer 20

salt and hydrogen

Question 21

what is the reactivity series of metals?

Answer 21

potassium 
sodium 
calcium
magnesium 
aluminium 
zinc
iron
tin
lead
copper
mercury
silver 
gold

Question 22

where is carbon?

Answer 22

in between aluminium and zinc

Question 23

where is hydrogen?

Answer 23

in between lead and copper

Question 24

what metals react with cold water, steam and acid?

3

Answer 24

potassium, sodium and calcium

Question 25

what metals react with steam and acid? | 4

Answer 25

magnesium, aluminium, zinc and iron

Question 26

what metals react with acid? | 2

Answer 26

tin and lead

Question 27

what metals are unreactive? | 4

Answer 27

copper, mercury, silver and gold

Question 28

what metals can be extracted by electrolysis? | 5

Answer 28

potassium to aluminium

Question 29

what metals can be extracted by heating with carbon?

Answer 29

zinc to gold

Question 30

what metals can be extracted by heating with hydrogen?

Answer 30

last 4 metals

Question 31

what is needed in the extraction of iron?

Answer 31

hematite, coke and limestone

Question 32

what is the first extraction of iron equation and what does it do?

Answer 32

C + O2 -> CO2 | production of carbon monoxide from burning coke in hot air

Question 33

what is the second extraction of iron equation and what does it do?

Answer 33

CO2 + C -> 2CO | production of carbon monoxide through the reaction of carbon dioxide with coke

Question 34

what is the third extraction of iron equation and what does it do?

Answer 34

3CO + Fe2O3 -> 2Fe +3CO2 | reduction of iron (III) oxide by carbon monoxide reducing iron (III) oxide to iron

Question 35

what is the first equation in the removal of impurities and what does it do?

Answer 35

CaCO3 -> CaO + CO2 | the decomposition of limestone

Question 36

what is the second equation in the removal of impurities and what does it do?

Answer 36

Cao + SiO2 -> CaSiO3 | the reaction of calcium oxide with silicon oxide which is a basic oxide and acidic oxide which forms slag

Question 37

what metals rust?

Answer 37

iron and steel

Question 38

what about other metals?

Answer 38

corrosion

Question 39

what are the condition for rusting?

Answer 39

- air, oxygen | - water, dissolved salt speeds up rusting (seawater)

Question 40

what are ways to prevent rusting?

Answer 40

- surface protection - sacrificial protection - galvanising

Question 41

what are some examples of surface protection?

Answer 41

- painting on street poles - oiling or greasing machinery - coating with plastic on metal clips - metal plating on food cana

Question 42

explain sacrificial protection

Answer 42

- happens when a more reactive metal reacts in place of a less reactive metal - the two metals must be touching each other - for instance, when magnesium and iron are in touch with each other, magnesium reacts in place of iron, it ‘sacrifices’ itself for iron

Question 43

explain galvanising

Answer 43

- happens when zinc is coated on top of a more reactive metal - the zinc reacts in place of the more reactive metal and is used up instead of the more reactive metal

Question 44

what is a practical application of galvanising?

Answer 44

zinc roofing

Question 45

what is one way to conserving metals?

Answer 45

recycling

Question 46

what is one way of recycling metals

Answer 46

using other materials in its place e.g glass bottles instead of metal cans

Question 47

what are some benefits of recycling metals?

Answer 47

- conserves limited supply of metals - saves costs of extracting new metals - prevents land pollution from the careless disposition of metals - recycling produces less pollution than extracting

Question 48

what are some disadvantages of recycling metals?

Answer 48

- metals are only recycled if it’s economical to do so - can cause air pollution from melting of scrap metal - cost of separating metals from waste can be high - costs money to collect scrap metals - can be difficult to persuade people to deposit materials in recycling containers