What are the five main types of material?
- Metals
- Plastics
- Glass
- Wood
- Fabric
What are the key properties of metal?
Strong and hard (usually), good conductors of heat and electricity, some can be magnetic.
What are the key properties of plastic?
Made from chemicals (not natural). Strong and waterproof. Good insulators of heat and electricity.
What are the key properties of glass?
Transparent and can be made into different shapes. Strength depends on thickness.
What are the key properties of wood?
Strong, flexible and long-lasting. Insulates heat and electricity.
What are the key properties of fabric?
Made of fibres woven together. Can have a range of properties to suit different purposes.
What is a solution?
a soluble substance (such as salt) mixed in water until it becomes transparent.
What are three possible methods of separating a mixture?
- Sieving - best used for a mixture of solid particles of different sizes eg. separating sand from gravel
- Filtering - best used for separating a mixture of solid particles and water
- Evaporating - best used for separating soluble substances from water
What is an irreversible change?
A change that can not be turned back again. For example, you cannot uncook an egg or unburn a piece of wood.
What are the three states of matter?
- Solids - stay in one place and can be held, they always take up the same amount of space
- Liquids - flow and cannot easily be held, a liquid will take the shape of the container it is held in but will always take up the same volume
- Gases - often invisible, with no fixed shape, they spread out to fill up whatever they are contained within
What is melting?
When some solids are heated, they change state to become a liquid, this is called melting
What is freezing?
When liquids are cooled they can change state to become a solid, this is called freezing
What is evaporation?
If a liquid is heated, it can change state to become a gas, this is called evaporation
What is condensation?
When a gas is cooled, it can change state to become a liquid
What are the stages of the water cycle?
- Evaporation - water on land gets heated by the sun and turns into water vapour, rising into the air
- Condensation - water vapour cools down in the air and changes back to tiny liquid drops forming clouds
- Precipitation - the clouds get heavy and the water they hold gets dropped back to the ground as rain or snow
- The cycle starts again
What is a fossil?
Preserved remains of a dead organism.
What are fossil records?
When fossils are found, we can tell how old they are by the rock they are surrounded by. This helps us to understand how living things have changed over time.
What is soil made from?
Tiny particles of rock, dead plants and animals, air and water.
The amounts of each of these parts present in soil give it its properties.
What are rocks?
Different rocks have different properties. Some are hard, some are soft, some are permeable, some are non permeable.
The properties of a rock determines its use.
What are the three types of rock?
- Sedimentary - layers of sand, dead plants, animal skeletons etc. squashed together
- Metamorphic - formed from other rocks that are changed by heat and pressure underground
- Igneous - made when molten rock cools and solidifies
