GCSE Revision: Metal Alloys, Their Properties and Uses

Science Quiz - Chemistry - Alloys (AQA) (Questions)

Alloys are mixtures of metals, or metals with other elements, designed to improve strength, hardness or resistance to corrosion compared with the pure metals used alone.

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Fascinating Fact:

Steel is iron with carbon. Low carbon steel is softer and easy to shape, high carbon steel is harder and more brittle.

In GCSE Science (Chemistry), you learn how alloys are made by mixing metals with other elements. This changes their properties so they are better for buildings, tools, vehicles and everyday products.

Key Terms

Alloy: A mixture of a metal with other metals or elements to give useful properties.
Pure metal: A metal made of only one type of atom, such as pure iron or pure copper.
Property: A characteristic of a material, such as strength, hardness, melting point or resistance to corrosion.

Frequently Asked Questions (Click to see answers)

What is an alloy in GCSE Chemistry?

An alloy is a mixture of a metal with other metals or elements. The different atoms disrupt the structure so the alloy gains improved properties compared with the pure metal.

Why are alloys often harder than pure metals?

Alloys are often harder because the different sized atoms make it more difficult for layers in the metal structure to slide. This increased resistance to sliding makes the alloy harder and stronger.

What are some common examples of alloys?

Common alloys include brass (copper and zinc), bronze (copper and tin), stainless steel (iron with chromium and nickel) and solder (a mixture such as tin and lead or tin and silver).

Try These Related Quizzes

What is an alloy?

[ ]	A mixture of metals
[ ]	A mixture of non-metals
[ ]	A mixture of a metal with either non-metals or other metals
[ ]	A pure metal that has been shaped in a certain way

Which of the following is not a reason for making an alloy?

[ ]	To make a material that is transparent to light waves
[ ]	To make a corrosion resistant material
[ ]	To make a harder material
[ ]	To make a more malleable material

Aluminium is a light metal but why is it not used to make aircraft?

[ ]	It is too brittle
[ ]	It corrodes too easily
[ ]	It is too weak
[ ]	It conducts electricity

Why are alloys stronger than the materials from which they are made?

[ ]	They contain different sized atoms that 'lock' the structure
[ ]	This is only true if you use a strong metal with a weak one
[ ]	They form a chemical compound
[ ]	The heat needed to make them gives alloys their greater strength

Why are 'silver' coins made from an alloy or nickel plated steel and not from silver?

[ ]	Silver is too valuable
[ ]	People would keep silver coins instead of spending them
[ ]	It is too difficult to get silver into the right size and shape
[ ]	Silver is too soft

Brass is an alloy of 70 per cent copper and 30 per cent zinc. Which of the following is not a use of brass?

[ ]	In electrical fittings
[ ]	In boat fittings
[ ]	In aircraft frames
[ ]	In musical instruments

Why does iron directly from a blast furnace have limited usefulness?

[ ]	It is too hot
[ ]	It is in the form of a big ingot
[ ]	It contains about 4% impurities, including carbon
[ ]	It is too soft

How is the percentage of carbon in pig iron reduced to form steels?

[ ]	By burning it off using oxygen
[ ]	By filtering it out
[ ]	By dissolving it in sulfuric acid
[ ]	By scraping it off the surface of the metal

Which of the following is a use of mild steel?

[ ]	Boat fittings
[ ]	Aircraft body panels
[ ]	Cables for large cranes
[ ]	All of the above

10.

Which of the following is a use of high carbon steel?

[ ]	Cutting tools
[ ]	Car body panels
[ ]	Furniture
[ ]	None of the above

Science Quiz - Chemistry - Alloys (AQA) (Answers)

What is an alloy?

[ ]	A mixture of metals
[ ]	A mixture of non-metals
[x]	A mixture of a metal with either non-metals or other metals
[ ]	A pure metal that has been shaped in a certain way

Quite often, there is only a very small percentage of the added metal or non-metal in an alloy

Which of the following is not a reason for making an alloy?

[x]	To make a material that is transparent to light waves
[ ]	To make a corrosion resistant material
[ ]	To make a harder material
[ ]	To make a more malleable material

There are many more good reasons for making alloys instead of using just the metal, e.g. to make it stronger, more ductile or less dense

Aluminium is a light metal but why is it not used to make aircraft?

[ ]	It is too brittle
[ ]	It corrodes too easily
[x]	It is too weak
[ ]	It conducts electricity

Mixing it with small quantities of other metals increases its strength and durability

Why are alloys stronger than the materials from which they are made?

[x]	They contain different sized atoms that 'lock' the structure
[ ]	This is only true if you use a strong metal with a weak one
[ ]	They form a chemical compound
[ ]	The heat needed to make them gives alloys their greater strength

Metals are made up from layers of atoms that are able to slide past each other. Adding the different sized atoms makes it a lot harder for this to happen, thus increasing the metal's strength

Why are 'silver' coins made from an alloy or nickel plated steel and not from silver?

[ ]	Silver is too valuable
[ ]	People would keep silver coins instead of spending them
[ ]	It is too difficult to get silver into the right size and shape
[x]	Silver is too soft

Pure silver coins are easily defaced and lose weight rapidly because the silver gets rubbed away. The alloy used for making 'silver' coins is cupro-nickel

Brass is an alloy of 70 per cent copper and 30 per cent zinc. Which of the following is not a use of brass?

[ ]	In electrical fittings
[ ]	In boat fittings
[x]	In aircraft frames
[ ]	In musical instruments

Brass conducts electricity well and is resistant to corrosion. It can be polished easily and resembles gold. It is hard to find something that hasn't been made of brass. Although some brass is used in aircraft, it is not normally part of the aircraft framework or skin as these require much lighter alloys

Why does iron directly from a blast furnace have limited usefulness?

[ ]	It is too hot
[ ]	It is in the form of a big ingot
[x]	It contains about 4% impurities, including carbon
[ ]	It is too soft

The impurities and the carbon make the iron very brittle. The impurities and at least half of the carbon have to be removed before it can be turned into anything useful. Iron direct from the blast furnace is called 'pig iron'

How is the percentage of carbon in pig iron reduced to form steels?

[x]	By burning it off using oxygen
[ ]	By filtering it out
[ ]	By dissolving it in sulfuric acid
[ ]	By scraping it off the surface of the metal

It is converted to carbon dioxide. At the same time, other impurities are removed