Particle Model of Matter Flashcards
(34 cards)
What density tell us?
What the substance is made up of and how particles are arranged
Equation for density
Density= mass/volume
Methods to work out density
- Measuring cylinder
2. Eureka can
Density of regular solid
- Use ruler to measure width, length and height of object
- Measure mass of object
- Use calculations to work out density
Density of irregular objects
- Measure mass of object
- Fill displacement / eureka can until water is level with bottom of pipe
- Place a beaker or measuring cylinder under pipe to collect displaced water
- Carefully drop the object into the CA and wait the water stops running into beaker or measuring cylinder
- Measure volume of displaced water
- Use measurements to find density
Density for liquid
- Measure mass of cylinder and pour liquid into it
- Measure mass of cylinder with liquid and find difference.
- Use measurements to find density
What happens when you heat a substance?
Particles get more kinetic energy and move faster, increasing internal energy
What temperature is absolute zero
-270 degrees Celsius
Why does a material become less dense when heated up?
Particles in the material move more and get further apart
What happens when materials cools down?
Particles move less and get closer together and the force of attraction increases, to make material more dense
What depends on how close particles are to each other?
Strength of the force of attraction
What is internal energy?
Energy stored by particles that make up a system ( their kinetic + potential energy total)
What is specific heat capacity?
Amount of energy needed to raise the temperature of 1kg of a substance by 1 degrees Celsius
How are changes in state happen?
Particles have enough energy in their kinetic store to break the bonds holding them together
What happens when a substance is melting or boiling?
You are still putting energy, increasing the internal energy but the energy isn’t used to raise temperature, instead to raise the break the bonds between particles
What happens when a substances condensing or freezing?
It releases energy and the internal energy decreases but the temperature doesn’t decrease until the substance has changed to liquid or solid
What is the specific latent heat?
Amount of energy needed to change 1kg of a substance form one state to another without changing the temperature
What is specific latent heat of fusion?
Specific latent heat for changing between a solid and liquid ( melting and freezing)
What is specific latent heat of vaporisation?
Specific latent heat for changing between liquid and gas ( evaporating, boiling and condensing)
What happens when you increase the temperature of a gas ?
The average speed of its particles increase
What is gas pressure?
Total force exerted by all of particles on a unit area f the container walls
What are pressure and volume?
Inversely proportional
What happens when you do work on a gas?
Increases its internal energy to increase the temperature
Arrangement of solids
Strong forces of attraction keep the particles in fixed, regular arrangement and vibrating in their fixed position
