Metals have many uses. The chemical and physical properties of materials are linked to their use.
The properties of metals are listed below.
Can you match the correct property with the definition in the table below?
| Definition | Property |
|---|---|
| All metals are shiny when polished | |
| Metals do not break - they bend | |
| Metals can be drawn into wires | |
| Metals can be hammered into sheets | |
| Metals ring like a bell when hit - they do not make a dull thud | |
| All metals conduct electricity | |
| Metals allow energy to flow through them, causing heating |
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 show the reactivity of some of the elements.
Certain metals when they react with water are also capable of producing hydrogen from 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.
Copy the table below into your notes:
| Metal | Reaction with Water | Test for Hydrogen |
|---|---|---|
| magnesium | ||
| iron | ||
| calcium |
Collect the following equipment:
Watch your teacher demonstrate this experiment then follow the instruction below:
Do the following:
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.
Copy the table below:
| metal | observation |
|---|---|
| magnesium | |
| iron | |
| tin | |
| zinc | |
| copper | |
| aluminium |
Collect the equipment below:
Watch your teacher demonstrate the experiment then follow the instructions below:
To solve the anagram put the first letter of the metal's name in order of reactivity.
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:
Equipment
Instructions
Plastics are made from giant molecules called polymers.
Polymers are made in a process called Polymerisation. In this process many thousand small molecules called monomers are joined together.
Poly means many.
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 | |
| polybutadiene | |
| phenylethene | |
| polyurethene | |
| polychlorothene |
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 available are of low cost but 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 fartilisers can be expensive to produce, can cause pollution but can be made in large quantities and can be made to suit particular crops.
To be an effective fertiliser a compound must contain nitrgogen, 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 | ||
| aluminium phosphate | ||
| potassium nitrate |
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-Muler tube.
Sources of background radiation are all around us. These sources include: