Triple Physics GCSE AQA Grade 9 Unit 3 Particle Model of Matter Notes

Unit 3: Particle Model of Matter
States of Matter
 There are three states of matter:
- Solids:
 Incompressible
 Contain particles in a fixed pattern
 Have a fixed size and shape
- Liquids
 Incompressible
 Have a fixed size
 Contain particles that are free to move
 This allows them to change shape to fit their container
- Gases
 Have large gaps between the particles
 Making them compressible
 Enables them to change size and shape



3 mass (m , kg)
Density: the mass per unit volume of a material. density ( ρ ,kg / m )= 3
volume(V , m )
- Increase density by decreasing the volume, or increasing the mass by maintaining
volume
Required Practical: Investigating the density of regular/irregular solids and liquids

Set the equipment up as shown. Independent variable: material
Record the height of the water in the measuring cylinder being testedDependant variable:
and the mass of the solid/liquid being tested. the volume and massControl
Add the solid/liquid being tested to the measuring cylinder. variable:
Record the new height in the measuring cylinder. temperatureHazards/Risks: - very
Subtracting the original height from the new height gives few hazards, unless the materials
the volume of the solid/liquid being tested. being tested are hazardous or
Now the density can be calculated. react with water- the main
Or use a eureka can, V displaced = volume of solid. hazard could be a slip hazard if
water is spilt.



Considerations, Mistakes and Errors:
If a solid that is less dense than water is tested, the volume measurement will be incorrect
because the solid will not be fully submerged.
Reading from the measuring cylinder should be taken from the meniscus.
The temperature of water must be controlled as an increase could cause the material or water to
change volume slightly through expansion.