metals

Question 1

what is rust

Answer 1

where iron is oxidised

Question 2

chemical name for rust

Answer 2

hydrated iron (III) oxide

Question 3

what two substances and two stages does rust require to form

Answer 3

1. oxygen - iron is oxidised by oxygen
2. water - iron oxide is hydrated by water

Question 4

how can rust be prevented

Answer 4

1. using barriers - prevents iron from coming into contact with oxygen or water, for e.g. oil, grease, paint or plastic
2. sacrificial protection - where you attach a more reactive metal to the iron, it displaces the iron from rust as soon as the rust forms
3. galvanising - coating the iron with zinc, even if crack appears zinc is more reactive so it also acts as sacrificial protection

Question 5

define ‘alloy’

Answer 5

mixture of a metal with one or more other elements

Question 6

why are alloys harder than pure metals

Answer 6

different sized atoms/ions prevent the layers of
metal ions from sliding over each other, so the alloy is less malleable

Question 7

what is the alloy ‘steel’ composed of

Answer 7

iron and carbon

Question 8

where are most metals found

Answer 8

in the earth’s crust as compounds with oxygen and sulphur

Question 9

what are rocks containing metal compounds called

Answer 9

ore

Question 10

why do native metals not need to be chemically extracted

Answer 10

because they already exist on their own

Question 11

what are native metals

Answer 11

gold and silver - too unreactive
native = uncombined

Question 12

metals more reactive than carbon cannot be displaced by carbon, so how to you chemically extract them?

Answer 12

by using electricity

Question 13

metals less reactive than carbon can be displaced by carbon, so how does it work?

Answer 13

by heating with carbon

Question 14

define ‘reduction’ in terms of oxygen

Answer 14

loss of oxygen

Question 15

define ‘reducing agent’ in terms of oxygen

Answer 15

takes oxygen away from something else

Question 16

define ‘oxidation’ in terms of oxygen

Answer 16

gain of oxygen

Question 17

define ‘oxidising agent’ in terms of oxygen

Answer 17

gives oxygen to something else

Question 18

define ‘redox’

Answer 18

where reduction and oxidation are in the same reaction

Question 19

fill in the blank: more reactive elements can ________ less reactive elements from their compounds

Answer 19

displace

Question 20

observations for magnesium + copper sulphate → copper + magnesium sulphate

Answer 20

1. Solid - turns from grey to pink-orange.
2. Solution - turns from blue to colourless.

Question 21

what happens to the non metal part in a displacement reaction?

Answer 21

remains unchanged

Question 22

acid + metal -> ?

Answer 22

salt + hydrogen

Question 23

test for hydrogen

Answer 23

lit splint -> squeaky pop

Question 24

what observations can be made in a metal + acid reaction?

Answer 24

the metal disappears and there is fizzing

Question 25

fill in the blank: the ____ reactive a metal is, the ______ it will react with an acid

Answer 25

more, faster

Question 26

metal + water -> ?

Answer 26

metal hydroxide + hydrogen

Question 27

what observations can be made in a metal + water reaction?

Answer 27

effervescence and the solid disappears

Question 28

what are metals in group 1

Answer 28

alkali metals

Question 29

what do alkali metals do?

Answer 29

react violently with water to form metal hydroxides and hydrogen

Question 30

what observations can be made with Li, Na and K with water?

Answer 30

the solid floats, effervescence, solid moves, solid disappears

Question 31

observation for Li + water

Answer 31

reaction is fast

Question 32

observation for Na + water

Answer 32

reaction is faster than Li, Na melts

Question 33

observation for K + water

Answer 33

reaction is fastest, K melts, lilac flame

Question 34

fill in the blank: group 1 metals get ____ reactive as you go ____ the group

Answer 34

more, down

Question 35

what happens when a group 1 metal reacts, and why

Answer 35

loses its outer shell to get a full outer shell
because :
1. the atoms get bigger and have more shells
2. so the outer-electron is further from the nucleus
3. so the attraction between the nucleus and the outer-electron is weaker
4. therefore less energy is needed to break the attraction

Question 36

metal + steam -> ?

Answer 36

metal oxide + hydrogen

Question 37

why do metals react with cold water and hot steam to produce different products?

Answer 37

steam has more energy, so both bonds in the water molecule can break

Question 38

metal carbonate -> ?

Answer 38

metal oxide + carbon dioxide

Question 39

what is a thermal decomposition reaction?

Answer 39

where heat energy is used to break down a substance

Question 40

appearance of thermal decomposition of copper carbonate

Answer 40

green solid -> black solid + colourless gas

Question 41

fill in the blank: carbon dioxide is ______ than air, so it is often collected by ________ delivery, which means that it _____ to the bottom of the tube

Answer 41

denser, downward, sinks

Question 42

describe the structure of a metal

Answer 42

lattice of positive metal ions with delocalised outer electrons

Question 43

define ‘metallic bonding’

Answer 43

electrostatic attraction between positive metal ions and negative delocalised electrons

Question 44

why do metals have high melting and boiling points?

Answer 44

because the metallic bonding is very strong so lots of energy is needed to break it

Question 45

why are metals good conductors of electricity?

Answer 45

the charged delocalised electrons are free to move

Question 46

why are metals good conductors of heat?

Answer 46

the delocalised outer electrons move freely through the lattice carrying heat energy quickly

Question 47

why are metals malleable?

Answer 47

the metal ions form layers which can slide over eachother