Alloys

Question 1

What percentage of cast iron (extracted using a blast burnace) is pure iron?

Answer 1

96%

Question 2

What is the remaining percentage of cast iron?

Answer 2

Impurities such as carbon

Question 3

What is one of hte only uses for cast iron?

Answer 3

Making ornamental railings

Question 4

State a property of cast iron and how it affects its usefulness

Answer 4

Brittle

Not useful for many purposes

Question 5

____ the impurities are removed from the blast furnace iron

Answer 5

All the impurities are removed from the blast furnace iron

Question 6

Describe the atomic arrangement of pure iron

What properties does this cause, and what is the effect of it?

Answer 6

Regular arrangment of identical atoms

The layers of atoms can slide over each other, making it soft and very malleable.

So pure iron is too bendy for most uses

Question 7

What is most iron used for?

Answer 7

Making into alloys called steels

Question 8

How are steels formed?

Answer 8

By adding small amounts of carbon and sometimes other metals to the iron

Question 9

Name the:

Type and amount of impurity

Property

Uses

of low carbon steel

Answer 9

Type and amount of impurity:

0.1% carbon

Property:

Easily shaped

Uses:

Car bodies

Question 10

Name the:

Type and amount of impurity

Properties

Uses

of high carbon steel

Answer 10

Type and amount of impurity:

1.5% carbon

Property:

Very hard, inflexible

Uses:

1. Blades for cutting tools
2. Bridges

Question 11

Name the:

Type of impurity

Property

Uses

of stainless steel

Answer 11

Type of impurity:

Chromium, sometimes nickel

Property:

Corrosion-resistant

Uses:

1. Cutlery
2. Containers for corrosive substances

Question 12

Name a problematic property of iron

Answer 12

It goes rusty if it is exposed to ait and water

Question 13

Alloys are ____ than pure metals

Answer 13

Alloys are harder than pure metals

Question 14

Explain, using the arrangement of atoms, why alloys are harder than pure metals

Answer 14

The regular arrangement of the metal atoms is disrupted by the addition of other different sized elements, which upset the layers of atoms, making it harder for them to slide over each other.

So alloys are harder

Question 15

What is bronze an alloy of?

Answer 15

Copper and tin

Question 16

Why might you want to create bronze instead of using copper?

When might you want to use bronze?

Answer 16

Bronze is harder than copper

Good for making medals and statues from

Question 17

What is cupronickel an alloy of?

Answer 17

Copper and nickle

Question 18

Name 2 useful properties of cupronickel

Answer 18

1. Hard
2. Corrosion resistant

Question 19

What is cupronickel used for?

Answer 19

To make ‘silver’ coins

Question 20

Why are gold alloys used to make jewellery?

Answer 20

Pure gold is too soft

Question 21

Name 5 metals that are added to gold to make it harder

Answer 21

1. Zinc
2. Copper
3. Silver
4. Palladium
5. Nickel

Question 22

Aluminium alloys are used to make ____

Answer 22

Aluminium alloys are used to make aircraft

Question 23

What property of alluminium makes it good for use in making aircraft?

What property lets it down, and what is done about this?

Answer 23

It has a low density

It is alloyed with small amounts of other metals to make it stronger

Question 24

Now we understand a lot about the ____ of metals, alloys can be ____ for ____ ____

Answer 24

Now we understand a lot about the properties of metals, alloys can be designed for specific uses

Question 25

Give 2 general examples of when you might want to make an alloy

Answer 25

1. Make it a lot harder than the original metal
2. Make it less brittle than the original metal

Question 26

Why are alloys generally so great?

Answer 26

Their properties can be varied and they can be made to suit a particular job really well