Paper 1

• solid are arranged in a regular pattern. The particles in a solid have kinetic energy because they are vibrating.
• The particles in a liquid or gas have kinetic energy because they move around
• Temperature is a measure of the average kinetic energy of the particles in a substance
• Change in eternal energy is change in temperature x mass x capacity
• Conduction primarily takes place in solids
• How conduction works


  1. One end of a solid object is heated

  2. Energy is transferred to the kinetic energy stores of the particles in that end

  3. Particles vibrate faster

  4. Particles collide with their neighbouring particles more often

  5. Collisions transfer kinetic energy to neighbours

  6. Neighbours vibrate faster and collide more often with their neighbours

  7. Process repeats over and over again

  8. Energy is effectively passed along the object from one particle to the next
• A fluid is a substance in which the particles are free to move around. They include both liquids and gases
• How convection works

  1. As a fluid is heated the particles gain kinetic energy and spread further apart.
  2. This causes the fluid to become less dense and so it will rise above any cooler fluid that hasn't been heated (because that fluid is more dense).
  3. As the fluid cools down it will become more dense again, and so sink back down.
  4. If this process takes place in a limited space, like a container or a room, it can create a convection current.
• Cavity walls trap air because air is a good insulator
• Efficiency = useful output divided by total input
• Pros of fossil fuels


  Relatively cheap

  Can be used in any condition

  Most of our current infrastructure is designed to run using fossil fuels 
• Cons of fossil fuels

  Non-renewable (limited source/finite)

  CO2 emissions

  Toxic gases
• Pros of nuclear energy

  No pollutants

  Used in any condition

  Although it’s finite, it’s unlikely to run out for a very long time
• Cons of nuclear

  Expensive

  Waste

  Dangerous (nuclear meltdown)

  Finite

  Plants take a long time to build
• Things to consider with fuels

  Expense running

  Expense setting up

  Renewable or finite

  Reliability

  CO2
• As the particles vibrate more, some of the forces of attraction between are overcome, causing the solid to melt into a liquid
• Pressure is measured in Pascals (Pa)
• In a solid, particles are arranged in a regular lattice structure and can only vibrate in place
• Density is mass over volume
• units of density


  kg/m3
• Density practical

  1. Measure the mass of the solid using a balance.
  2. If the shape is regular, measure the volume of the solid using geometry.
  3. If the shape is irregular, measure the volume of the solid by adding it to a Eureka can filled with water. This will cause a volume of water exactly equal to the volume of the solid to flow into the measuring cylinder.
  4. Use the formula to calculate the density of the solid from the mass and volume measurements
• The greater the pressure on a fluid, the greater its density.
• A change in temperature causes a change in density because as the temperature increases, the kinetic energy of the molecules also increases, so they move faster and further apart. The increased distance between them means that there is less force of attraction between them, which reduces their density.
• Pressure = Force / Area (Pa)
• When a substance changes state from a liquid to a gas, it's called boiling. During boiling, heat energy is used to break the forces holding the particles together
• The specific latent heat is the energy required to change 1kg of a particular substance from one state to another, without a change in temperature
• The specific latent heat of fusion refers to when a substance changes from a solid to a liquid (or vice versa)
• The specific latent heat of vaporisation refers to when a substance changes from a liquid to a gas (or vice versa)
• Specific latent heat formula

  energy = mass x slh
• When kept at a constant temperature, the pressure and volume of a gas are inversely proportional.
• A radioactive material has unstable isotopes that can decay
• An alpha particle is 2 protons and 2 neutrons
• Beta particles are one electron
• A gamma ray is a high energy electromagnetic wave that is emitted by the nucleus of an atom
• when a nucleus has too many neutrons making it unstable, a neutron is emitted
• Alpha particles can’t penetrate paper

  Beta can penetrate paper but cannot penetrate 5mm of aluminium

  Gamma can penetrate aluminium but cannot penetrate thick lead
• Source of a beta particle

  A neutron decaying into a proton and an electron
• Alpha is the most ionising
• Decay is random for a single atom
• 'Activity' is the overall rate of decay of all of the radioactive isotopes in our sample