The Particle Model Flashcards
What are the densities of solids liquids and gases
Solids have similar densities as the space between particles doesn’t change significantly
Usually liquids have a lower density however
Gases have a far lower density as the spacing between atoms increases as the particles have lots of energy to move so volume increases greatly compared to solids and liquids
What is the required practical for the density of a regular object
1) Measure the length, width and height of the object using a ruler recording your values to the nearest millimetre
2) Calculate the volume by multiplying the l, w and h giving your value in cm3
3) Measure the mass of the object using a balance. Remember to reset the balance with nothing on the scales to reduce zero error
4) calculate the density using the equation mass divided by volume
What is the required practical of calculating the density of an irregular shaped object
1) Fill the eureka can with water until the spout drips with water. Align the measuring beaker with the spout
2) place the irregular shaped object slowly into the can ensuring not to drop it from a height it cause it ti splash
3) collect the displaced water in a beaker and measure the volume of water displaced using a measuring cylinder
The volume of water displaced is equal to the volume of the object thag caused the displacement
4) measure the mass of the object using a balance
5) calculate the density using density is mass divided by volume
What happens during a change of state
Mass if conserved
Changes if state are physical changes which differ from chemical changes as the material recovers its original properties if the change is reversed
What is internal energy
Energy stored inside a system by the particles that make up a system
What happens when heating a system
Heating increased the energy the particles have which increased internal energy. This either raises temperature of the system or produces a change of state
What is specific heat capacity
Amount of energy needed to raise the temp of 1 kg of the substance by 1’degree celcius
What is specific latent heat
Amount of energy needed to change the state of 1 kg of a substance with no change in temo
What is specific latent heat of fusion and vaporisation
Fusions- solid to liquid
Vaporisation - liquid to vapour
Why would there be no temp change on a graph
Energy is used through melting, evaporation etc
What happens in motions of pressure
The higher the temperature the greater the average kinetic energy and so the faster the average speed of the molecules
When the molecules collide with the wall of their container they exert a force on the wall. The total force exerted by all of molecules inside the container on a unit area of the walls is gas pressure
Changing the temperature of a gas held at a constant volume changes the pressure exerted by the gas known as the pressure law
