Particle model of matter P1

Cards (27)

  • How do you fine the density of a solid (irregular) object?
    1. Using a balance measure its mass
    2. Submerge object in water in a eureka can filled with water.
    3. Water displaced by the object will be caught in a beaker and transferred to a measuring cylinder
    4. Record the volume of water in the cylinder
    5. Then use the formula Density= mass/volume
  • What are the properties of a solid?
    -Strong forces of attraction, which hold particles together in a fixed position
    -Regular arrangement
    -Not much energy particles only vibrate
    -Highest density
  • What are the properties of a liquid?
    -Weaker forces of attraction
    -More energy than solids
    -Irregular form
    -Less dense than solids
  • What are the properties of gas?
    -No forces of attraction
    -Particles have more energy than solids and liquids
    -Free to move- random direction
    -Low density
  • Why do particles in a system vibrate or move around?
    They have energy in their kinetic energy stores
  • What is internal energy?
    Total energy that its particles have in their kinetic and potential energy stores
  • How does a change in state occur?
    If the particles are heated enough they will have enough energy in their kinetic stores to break the bonds holding them together
  • How can a state change due to cooling?
    The particles loose energy and form bonds
  • Does change in state affect mass?
    No, the number of particles dont change- they're just arranged differently. Therefore mass is conserved.
  • What is specific latent heat?
    The amount of energy needed to change 1kg of a substance from one state to another without changing its temperature
  • When a substance is melting or boiling, what is the energy used for?
    Breaking bonds between particle- not raising the temprature.
  • What happens when a substance is condensing or freezing?
    Bonds are forming between particles, which releases energy. This means internal energy decreases.
  • What is specific latent heat for changing between a solid and a liquid called?
    Specific latent heat of fusion
  • What is specific latent heat for changing between a liquid and a gas called?

    Specific latent heat of vaporisation
  • Formula for specific latent heat
  • What happens if you increase the temperature of a gas?
    The average speed of its particles increases
  • Pressure and volume are inversely proportional
  • What happens when you do work (transfer energy by applying force)on a gas?
    Increases internal energy which can increase temp
  • What factor affects the average kinetic energy of gas molecules?
    ● The temperature of the substance
    ● The higher the temperature, the higher the average kinetic energy of the molecules
  • What effect does increasing temperature have in the pressure of a gas when help at a constant volume?
    Pressure of the gas will increase as the temperature increase
  • Why does pressure increase as temperature increases (at a constant volume)?
    Kinetic energy of molecules increases
    ● Collisions between molecules becomes more frequent
    ● Greater rate of change of momentum
    ● Greater force and therefore pressure
  • If gas A is at a low pressure, and gas B is at a high pressure, what can be said about the rate of collisions in each gas?

    ● There are more collisions per second in gas B than in gas A
    ● The rate of collisions is higher in B
  • Describe the force that the pressure of a gas exerts on the walls of its container.
    ● The net force acts at right-angles to the container’s surface
    ● The force increases as pressure increases
  • Explain how increasing the volume of a gas results in a decrease of pressure.
    ● Molecules become more spread out and so time between collisions increases
    ● This reduces the rate of collisions
    ● Rate of change of momentum decreases, and so force exerted on container decreases, resulting in a lower pressure
  • What can be said about the product of pressure and volume for a fixed mass of gas at a constant temperature?
    It is constant.
    p V = constant
  • What increases when you do work on a gas?
    ● The internal energy of the gas
    ● This can also lead to an increase of temperature
  • Why does the temperature of air inside a bike pump increase when it is pumped?
    ● Work is done on a gas when it is compressed
    ● Doing work on a gas increases its internal energy, so also increases the average kinetic energy of the molecules
    Temperature increases with an increase o