3.5 Metals

Question 1

Metallic structure

Answer 1

• A lattice of positive metals ions

- A ‘sea’ of delocalised electrons

Question 2

Metallic bonding

Answer 2

The electrostatic attraction between positive metals ions and (negative) delocalised electrons.

Question 3

Metallic bonding, strong

Answer 3

The strong electrostatic attraction between positive metals ions and (negative) delocalised electrons requires lots of energy to overcome

Question 4

Properties of metals

Answer 4

• High melting point
• Malleable
• Conducts electricity

Question 5

High melting point explanation

Answer 5

Strong electrostatic attraction between positive metals ions and (negative) delocalised electrons requires lots of energy to overcome

Question 6

Conducts electricity explanation

Answer 6

The delocalised electrons are free to move and can carry charge through the lattice

Question 7

Malleable explination

Answer 7

The layers of positive metal ions can slide over each other and the delocalised electrons keep the attraction

Question 8

Thermal decomposition

Answer 8

When heat energy is used to break down a substance

Question 9

Metal carbonate thermal decomposition

Answer 9

Metal carbonate —> Metal Oxide + Carbon Dioxide

Question 10

Thermal decomposition of copper carbonate

Answer 10

Copper Carbonate —> Copper Oxide + Carbon Dioxide

Question 11

Thermal decomposition of copper carbonate: Colour change

Answer 11

Green —> black solid (+ colourless gas)

Question 12

Downward delivery

Answer 12

Carbon dioxide is denser than air meaning it is collected by downward delivery. It sinks to the bottom until you want to use it.

Question 13

Metal + Water reaction

Answer 13

Metal + Water —> Metal Hydroxide + Hydrogen

Question 14

Metal + Water Reaction: Magnesium

Answer 14

Magnesium + Water —> Magnesium Hydroxide + Water

Question 15

Metal + Water Reaction: Observations

Answer 15

• Solid disappears as it is used up
• Fizzing as gas is given off (hydrogen)
• Metals that are less reactive react slower

Question 16

What are the group one metals called?

Answer 16

The alkali metals

Question 17

What do group 1 metals do?

Answer 17

They react violently with water to form metal hydroxides and hydrogen

Question 18

Observations of Reaction of Lithium, Sodium and Potassium in water

Answer 18

• Fizzing (hydrogen gas)
• Solid floats
• Solid moves
• Solid disappears

Question 19

What happens to the reactivity as you go down group 1?

Answer 19

The reactivity increases

Question 20

What are all metal hydroxides?

Answer 20

Alkalis as they have donated OH-

Question 21

What colour is the universal indicator after reaction of a group 1 metal with water?

Answer 21

Turns dark blue as they are alkali

Question 22

Observations of potassium reaction with water?

Answer 22

Lilac Flame and melts fastest

Question 23

Trend going down group 1

Answer 23

As you go down group one, there are more shells on each atom meaning it is easier to lose the outer electron as it’s further away from the nucleus. Therefore less energy is needed to break the attraction.

Question 24

What happens if you react a metal with steam

Answer 24

Doesn’t produce a metal hydroxide, only a metal oxide. This is because steam has more energy so both bonds in the water molecule can break.

Question 25

How are most metals found?

Answer 25

In the earths crust as compound with oxygen and sulphur, these are called ores

Question 26

Why are gold and silver metals special?

Answer 26

They are too unreactive to combine with oxygen and sulphur, they are found ‘native’ which means chemically uncombined

Question 27

Metal more reactive than carbon

Answer 27

If a metal is more reactive than carbon it has to be extracted using electrolysis

Question 28

Electrolysis

Answer 28

In water, molecules that are positive go to one side, and negative to another, separating them

Question 29

Carbon Extraction

Answer 29

-Heat with carbon and the metal is displaced by the carbon, this only works because it is more reactive than carbon.

Question 30

Carbon Extraction Example

Answer 30

Carbon + Copper Oxide —> Carbon Dioxide + Copper | Redox reaction

Question 31

Reduction

Answer 31

Loss of oxygen, Gain of electron

Question 32

Reducing Agent

Answer 32

Takes oxygen away from something else

Question 33

Oxidation

Answer 33

Gain of oxygen, Loss of electrons

Question 34

Oxidising Agent

Answer 34

Gives oxygen to something else

Question 35

Redox

Answer 35

When both oxidation and reduction occurs

Question 36

Rusting

Answer 36

When iron is oxidised to form rust

Question 37

Rusting requires two substances

Answer 37

Water and Oxygen

Question 38

Barrier method

Answer 38

Coat iron in paint, oil, grease or plastic so the water and oxygen can’t get into the iron But, the coat will wear away meaning it has to be replaced

Question 39

Sacrificial Protection

Answer 39

Attach a more reactive metal so it will displace the iron But, you need to replace the more reactive metal often (usually magnesium)

Question 40

Galvanising Method

Answer 40

Barrier method & Sacrificial protection combined, you coat the iron in zinc, it’s more reactive and water and oxygen can’t get in. But it is expensive and needs to be replaced.

Question 41

Alloy

Answer 41

Mixtures of a metal with one or more other elements (usually other metals or carbon)

Question 42

Alloy characteristics

Answer 42

Harder than pure metals because different sized atoms prevent the layers from sliding over each other (less malleable)

Question 43

Use of iron

Answer 43

Making steel as it’s more useful

Question 44

Low-Carbon steel use

Answer 44

Ships, Cars, Bridges, it’s strong but still can be hammered into shape

Question 45

High-Carbon steel use

Answer 45

Tools, less malleable and stiffer than low carbon steel

Question 46

Stainless steel use

Answer 46

Cooking pans, cutlery, kitchen sinks, (Cr forms oxide layer that resists corrosion meaning it’s shiny)

Question 47

Copper use

Answer 47

Wires, Water pipes (Conductor or heat and electricity, malleable)

Question 48

Aluminium use

Answer 48

Aircraft bodies, power cables (low density, high strength, conductors)