Metals - Properties and Uses of
Gold is very unreactive and relatively easy to shape, therefore good for making jewellery with.

Metals - Properties and Uses of

In this GCSE Chemistry quiz we take a look at some of the properties of metals, such as malleability and conductivity. We also find out about how the different properties of metals affect their uses. For example, how the softness and conductivity of copper make it the best material for electric wires.

The majority of the chemical elements are metals and their properties make them incredibly useful. Each metal has its own unique set of properties but there are general properties too, for example, they conduct heat, conduct electricity, are malleable and ductile. For the GCSE, you are expected to be able to link the properties of a metal to its uses, as in the above example with copper. Remember, copper is used for making electrical wires because it is one of the best conductors of electricity and is a soft metal, enabling the wires to be bent to get them into tight spaces. Most of the time, the uses of metals will can be worked out by a common sense application of what you know about the properties of metals in general, so make sure that you revise them. It is also useful to know the properties of certain specific metals like those of group one which react rapidly with water and mercury which is a liquid at room temperature.

The properties of metals come from their structure, their atoms are held together by metallic bonding. The atoms of metals are packed tightly together and as a result, some of the electrons in their outer shell (energy level) become detatched. These are referred to as delocalised electrons as they are then free to move anywhere through the metal instead of being attached locally to a specific ion or atom. The presence of these electrons goes a long way towards explaining why metals behave as they do. Metallic structure is often described as metal ions in a sea of electrons.

Take for example malleability and ductility. The closely packed metal ions are in fact arranged in layers. These layers can slide over each other which allows metals to bend or be pulled into thin wires without breaking. Since the ions are surrounded by a 'sea of electrons' it doesn`'t matter where they are, if they are moved, they will still be in the electron sea. So if we bend a metal, the layers on the outside of the bend will slide over those on the inside of the bend. But they will all be surrounded by the sea of electrons, so the overall structure of the metal will not be affected and it remains intact.

The structure of metals, including the presence of delocalised electrons, makes them good conductors of heat and electricity. Heat is transferred through the metal in two ways. Firstly, heat makes particles of matter vibrate - the more heat, the faster the vibration. Because the ions in a metal are so closely packed, these vibrations are soon passed along a metal from where it is warmer to where it is cooler. Secondly, the electrons will move around faster and they will carry the energy from the heat throughout a piece of metal. By comparison, in non-metals and compounds, the particles are much further apart and electrons are fixed in place. An electrical current is a flow of electrons and since the delocalised electrons are free to move throughout the metal, when you connect it to a power source to make an electrical circuit, the electrons can be 'pumped' through the ciruit.

Which metal is the most appropriate to make jewellery from?
Gold is very unreactive and relatively easy to shape since it is a soft metal. It is usually mixed with other metals like copper to make alloys. You can tell the purity of a gold item from the hallmark, the lower the number of carats the less gold there is in the alloy
Which two of the following statements could explain why aluminium is preferred to iron for making cans for drinks?
Aluminium is a better conductor than iron
Aluminium is not as strong as iron
Aluminium has a lower melting point than iron
Aluminium corrodes less easily than iron
When answering questions like this, choose relevant properties
Why is iron better than aluminium for making bridges?
It is more easily painted
It is a better insulator
It has a higher density
It is harder
Aluminium is a soft metal. Alloying it with other metals to make it harder would be possible but it would be too expensive to use on the scale of even a small bridge
Why is gold used for jewellery?
It's expensive
It looks nice
It is unreactive
It's very hard
It wouldn't be very good if your gold jewellery was reactive with water!
Why is aluminium used to make aeroplane bodies?
It is shiny
It is very light
It is cheap
It is very abundant
It is actually aluminium alloys that are used as these are stonger and in some cases lighter than aluminium alone
Aluminium is a useful metal to use because it does not corrode easily in air. Why?
It is very unreactive
It has a protective layer of aluminium oxide on its surface which does not allow air or water to penetrate
It doesn't react with anything
It is very reactive
Aluminium is actually quite a reactive metal but when the oxide coating forms, it appears to be a lot less reactive than it is - if you have ever seen the thermite reaction then you will appreciate just how reactive aluminium really is
Why is potassium kept stored in oil?
It would react with the water in the air
To keep it shiny
To keep it lubricated
To see if it floats
Potassium is a highly reactive metal that reacts vigorously with water releasing hydrogen gas and forming potassium hydroxide. The reaction is highly exothermic and so much heat is given off that the hydrogen gas ignites. The flame appears purple because of the presence of burning potassium vapour
Copper is often used for water pipes and electrical wires. Pick two properties of copper which make it useful for this purpose.
Good conductor and malleable
Poor conductor and ductile
Nice colour and bendy
Shiny and thin
Malleable means that it can be bent or hammered into shape
Which metal would be the most appropriate to make overhead power lines from?
Aluminium is a very good conductor of electricity and a relatively light metal
Why is iron rarely used as pure iron?
It is too heavy
It is too expensive
It is too hard
It is too brittle
Pure iron is very hard but also very brittle. Small amounts of carbon (under about 4%) convert the iron into steel, which is much more malleable. Its properties can be changed even further by alloying it with other metals to make it stronger or lighter or corrosion resistant
You can find more about this topic by visiting BBC Bitesize - Metals and alloys

Author:  Kate Gardiner

© Copyright 2016-2023 - Education Quizzes
Work Innovate Ltd - Design | Development | Marketing

Valid HTML5

We use cookies to make your experience of our website better.

To comply with the new e-Privacy directive, we need to ask for your consent - I agree - No thanks - Find out more