Metals have many uses. The chemical and physical properties of materials are linked to their use.

The properties of metals are listed below.

• electrical conductor
• flexible
• sonorous
• ductile
• thermal conductor
• malleable
• lustrous

Can you match the correct property with the definition in the table below?

Definition	Property
All metals are shiny when polished	Answer lustrous
Metals do not break - they bend	Answer flexible
Metals can be drawn into wires	Answer ductile
Metals can be hammered into sheets	Answer malleable
Metals ring like a bell when hit - they do not make a dull thud	Answer sonorous
All metals conduct electricity	Answer electrical conductor
Metals allow energy to flow through them, causing heating	Answer thermal conductor

Ores and Reactivity

Some metals are more reactive than others. Metals are arranged in order of reactivity in the reactivity series.

Metals are often found in rocks called ores. However, some unreactive metals such as gold can be found as pure metals.

The video below shows the reactivity of some of the elements.

Reaction of Metals with Water

Certain metals when they react with water are also capable of producing hydrogen from water.

Activity - Alkali Metals Reacting With water

Watch your teacher demonstrate the alkali metals reacting with water.

The video below shows the bigger pieces of alkali metals reacting with water as well as some that can't be done in school.

Activity - Other Metals that React with Water

Copy the table below into your notes:

Metal	Reaction with Water	Test for Hydrogen
magnesium
iron
calcium

Collect the following equipment:

• safety mat and goggles
• test tube rack
• Bunsen burner
• 3 test tubes
• spatula
• a wooden splint

Watch your teacher demonstrate this experiment then follow the instruction below:

1. Add about 2 cm of water to each test tube.
2. Add magnesium to your first test tube.
3. Test to see if hydrogen gas is produced.
4. What did you see?
5. Write this down in your results table.
6. Do steps 1-5 again with calcium then with iron.

Results

Do the following:

1. Method: Draw a labelled diagram of your experiment and equipment.
2. Conclusion: copy and complete the conclusion below:

The metal that reacts most with water is c______.

The metal that reacts least with water is i___.

Some metals react with water to make h_______ gas.

Reaction of Metals with Acid

Copy the table below:

metal	observation
magnesium
iron
tin
zinc
copper
aluminium

Collect the equipment below:

• Safety mat & goggles
• Test tube rack
• 6 x Test tubes
• Spatula
• Heat mat
• Bunsen burner
• Splint

Watch your teacher demonstrate the experiment then follow the instructions below:

1. Collect a bottle of acid.
2. Add about 2cm of acid to each test tube.
3. Add one bit of magnesium to your first test tube.
4. Test to see if hydrogen has been given off.
5. Write what you see in your results table.
6. Repeat for the remaining metals.

Notes - Metals and Acids

Show solution

To solve the anagram put the first letter of the metal's name in order of reactivity.

Corrosion

Corrosion is a reaction that takes place on the surface of a metal.

There are various things that can be done to protect metals against corrosion. These include:

• painting - covering the metal with a layer of paint
• greasing - covering the metal with a layer of grease
• galvanising - covering the metal with a layer of zinc

Experiment - Preventing Corrosion (rust)

Equipment

• Eye protection
• 4 x Test tubes
• Test tube rack
• Vaseline
• Paint
• 3 x Iron nails
• 1 x Galvanised (zinc coated) nail

Instructions

1. Select 4 nails which do not show any signs of rusting. Clean them thoroughly with sand paper.
2. Place one nail as a control into a test tube.
3. Paint one nail and let it dry.
4. Coat one nail with Vaseline or other grease, or oil.
5. Place these nails in separate test tubes.
6. Set aside until next lesson
7. Carefully pour the corrosion indicator into each test tube, completely covering each nail. Leave for at least half an hour.

Learning Outcomes

1. Give examples of natural and synthetic fibres
2. State that most plastics and synthetic fibres are made from chemicals derived from oil.
3. State that synthetic materials are made by the chemical industry.

Note - Plastics

Chemists are involved in developing new and unusual materials to meet the demands of society. These materials need to have special and unique properties that improve the way we live.

Read - Plastics

Oil can be separated into many useful substances e.g., petrol, diesel and naphtha using fractional distillation. Naphtha is the fraction of oil that is used as the feedstock for making other substances. Oil is the raw material that is used to make plastics. Most of the plastics we use on a daily basis are made from chemicals obtained from: CRUDE OIL. Plastics are a group of important materials that have a variety of uses. Plastics can be made specifically to match the properties that are needed for the job that it has to do. Plastics are relatively new, synthetic materials. This means that they are not natural but man-made in the chemical industry.

Questions - Plastics

The uses of plastics are related to their chemical properties.

plastic	use

Plastics are made from giant molecules called polymers.

Polymers are made in a process called Polymerisation. In this process many thousands of small molecules called monomers are joined together.

Poly means many.

Naming Polymers

Adding 'poly' in front of the monomers name gives the polymers name.

Taking 'poly' away from the polymers name gives the monomers name.

Try the examples in the table below.

monomer	polymer
ethene	polyethene
propene	Answer polypropene
Answer butadiene	polybutadiene
phenylethene	Answer polyphenylethene
Answer urethane	polyurethane
Answer chloroethene	polychloroethene

Thermosoftening and thermosetting plastics

Thermosoftening plastics or thermoplastics can be reshaped on heating.

Thermosetting plastics cannot be reshaped on heating.

To grow well plants require nutrients. These nutrients contain the essential elements nitrogen (N), phosphorus (P) and potassium (K). Sometimes referred to as NPK.

Fertilisers can be natural or man made. Man made fertilisers are also known as synthetic fertilisers.

Natural fertilisers include animal manure, plant manure and compost. These are environmentally friendly as they make use of natural waste and are low cost, but they are not always available in the quantities needed.

Synthetic or man made fertilisers have been developed to contain the essential elements needed for plant growth. Examples include ammonium nitrate and potassium phosphate.

Synthetic/man-made fertilisers can be expensive to produce, can cause pollution but can be made in large quantities and can be made to suit particular crops.

Solubility

To be an effective fertiliser a compound must contain nitrogen, phosphorus or potassium as well as being soluble. The solubility of selected compounds can be found in the databook on page 8.

Use the databook to find out if the compounds below would make good fertilisers.

Compound	soluble or insoluble?	suitable as a fertiliser
ammonium nitrate	Answer soluble	Answer yes
aluminium phosphate	Answer insoluble	Answer no
potassium nitrate	Answer soluble	Answer yes

Experiment - Soil pH

Plants also need soil to be of the correct pH to grow. Soil pH can be tested with a pH meter like the one in the picture below.

Choose four areas within the school grounds to measure the soil pH with your pH meter. Record the location, soil pH and if a plant or tree is growing there.

Location	pH	plant or tree growing?

The French physicist Henri Becquerel discovered radioactivity in 1896 while doing experiments with uranium salts.

Radioactivity or radiation can be detected using a Geiger-Müller tube.

Sources of background radiation are all around us. These sources include:

• cosmic rays from space and the Sun
• rocks
• soil
• televisions
• smoke detectors