Particle model of matter

• How does changing the temperature of a gas affect its pressure?

  It changes the pressure of the gas
• What is the state of particles in a gas?

  They are very far apart and in constant motion
• What causes the pressure of a gas?

  Particles colliding with the walls of the container
• How can you increase the pressure of a gas?

  Increase collisions per second or collision energy
• What happens to gas pressure at low temperatures?

  Gas pressure is relatively low
• What happens to gas pressure at high temperatures?

  Gas pressure is relatively high
• What is the relationship between temperature and average kinetic energy of gas particles?

  Temperature is related to average kinetic energy
• What occurs to particle collisions at high temperatures?

  More collisions per second occur
• What type of collisions occur at low temperatures?

  Fewer and lower energy collisions
• How does the average kinetic energy of particles change with temperature?

  It increases with higher temperatures
• If the temperature of a gas is increased, what happens to the energy of the particles?

  The energy of the particles increases
• What is the effect of low kinetic energy on gas pressure?

  It results in lower gas pressure
• What is the effect of high kinetic energy on gas pressure?

  It results in higher gas pressure
• What does irradiation mean?

  Exposing an object to nuclear radiation
• Does an object become radioactive when irradiated?

  No, it does not become radioactive
• How can ionising radiation affect health?

  It can increase the risk of cancer
• What precautions must people working with radioactive isotopes take?

  They must take safety precautions
• What are the protective measures against radiation?

  • Gloves protect against alpha radiation
  • Lead walls provide shielding
  • Lead aprons reduce beta and gamma radiation
  • Lead glass screens offer additional protection
• What device is used to measure radiation exposure?

  A radiation monitor
• What is radioactive contamination?

  Unwanted radioactive isotopes on materials
• Why is radioactive contamination hazardous?

  Radioactive atoms decay and emit radiation
• What are the characteristics of different types of radiation?

  • Alpha: Strongly ionising, stopped by skin
  • Beta: Quite ionising, penetrates body
  • Gamma: Weakly ionising, passes through body
• What does density tell us about a material?

  The mass for a given volume
• What is the formula for density?

  Density = mass / volume
• What are the steps to measure the density of a regular object?

  1. Measure mass using a balance
  2. Measure the length of the cube
  3. Calculate volume and use density formula
• What are the steps to measure the density of an irregular object?

  1. Measure mass using a balance
  2. Fill a eureka can with water
  3. Submerge the object to displace water
  4. Measure the displaced water volume
• What is internal energy?

  Energy stored in a system by particles
• What does internal energy consist of?

  Total kinetic and potential energy of particles
• What happens to internal energy when a solid is heated?

  It increases, causing a phase change
• What is sublimation?

  Solid turning directly into gas
• What is specific latent heat?

  Energy required to change state without temperature change
• What is specific latent heat of fusion?

  Energy to change solid to liquid
• What is specific latent heat of vaporisation?

  Energy to change liquid to vapour