C 4 Alloys

Question 1

What is an alloy?

Answer 1

A mixture of a metal with one or more other elements (often other metals or non-metals) to improve its properties.

Question 2

Why are alloys often harder than pure metals?

Answer 2

Because the different-sized atoms distort the layers, making it harder for them to slide over each other.

Question 3

Give two examples of common alloys and what they are made from.

Answer 3

Bronze = copper + tin
Brass = copper + zinc

Question 4

What is steel made from?

Answer 4

Iron + small amounts of carbon (and sometimes other elements)

Question 5

Why is pure iron too soft for most uses?

Answer 5

Because its atoms are in layers that slide over each other easily, making it too malleable.

Question 6

How does adding carbon to iron make it stronger?

Answer 6

Carbon atoms disrupt the layers, so they can’t slide easily, making the steel stronger and harder.

Question 7

Name a type of steel and its use:

Answer 7

Stainless steel → used for cutlery and medical tools (resists corrosion)
High-carbon steel → used for cutting tools

Question 8

Why are alloys used more than pure metals in many applications?

Answer 8

Because they have better properties, such as increased strength, hardness, or resistance to corrosion.