1. Molecules and Matter

2. Molecules And Matter Ice Water Steam
All these substances are made from water molecules but all showing very different properties because …………….
One is a SOLID, one is a LIQUID and one is a GAS

3. How Molecules Are Arranged In A Solid
Solids – Hold their shape
Have a fixed volume
There are many bonds between molecules in solids.
The molecules are usually held in regular patterns

4. Liquids – Take up the shape of their container
Have a free side
Have a fixed volume
The molecules are able to move around each other. They have weak bonds attracting them to other molecules

5. Gasses – Expand, contract to the shape of the container.
Take up the shape of the container, don’t have a fixed volume
The molecules have very little attraction to each other. There are few bonds between molecules.

6. Add HEAT ENERGY to the SOLID and bonds become weaker producing a LIQUID

7. Add HEAT ENERGY to the liquid and the bonds break down producing a GAS

8. “When heated solids become a liquid”
“Liquids will flow and take up the shape of their container”
“When heated solids become a liquid”
These two points are important in technology because we can use these properties to form intricate shapes using metals. If we heat a metal up then pour it into a mould it will take up the shape of the mould and keep that shape as it cools and becomes solid.
This is called
CASTING

9. How Casting Works Remove the mould Produce a mould Large pouring spout
Cut away the pouring spout
Pour hot liquid metal into the cavity

10. Pewter Casting
A suitable metal to use is pewter and a simple mould can be made out of an MDF (medium density fibreboard) sandwich.
How the mould is formed
Thick layer
Mould
Thick Layer

11. The Mould This is the final MDF mould
Cavity layers. (this mould uses two)
Finished castings
Thicker outer layers
The spout has been cut in the thicker wood with a round surform

12. Safety Safety Safety Safety Safety
When pouring the HOT pewter
Wear gloves
Wear Goggles
Make sure nobody is near you
A reciprocating saw can be used to cut the mould. This needs
Goggles
The guard to be in place
Training

13. These castings are possible because heating a solid produces a liquid that can be poured. It will take up the shape of the mould and when it solidifies it will keep the shape of the mould.
These castings are possible because heating a solid produces a liquid that can be poured. It will take up the shape of the mould and when it solidifies it will keep the shape of the mould.