Physics Year 10 GCSE (unit 1.2-1.8)

• Specific heat capacity


  The energy required to heat 1kg of a substance by 1ºC
• Specific heat capacity of water


  • 4200 J/kg ºC
• ∆Q


  Change in thermal energy
• m


  Mass
• c


  Specific heat capacity
• ∆θ


  Change in temperature
• Specific latent heat


  The energy required to change the state of 1kg of a substance without a change in temperature
• Specific latent heat of fusion of ice

  • 336000J/kg
• Q


  Thermal energy for change in state
• L


  Specific latent heat
• Temperature changes of a block of ice

  1. A-B: Solid

  2. B-C: Melting

  3. C-D: Liquid

  4. D-E: Boiling

  5. E-F: Gas
• Solid state


  • Particles are packed very closely, vibrate in place but are not free to move
• Melting


  • Energy is used to break some of the bonds holding the particles in place
• Liquid state


  • Particles are close together but can move past each other
• Boiling


  • Energy is used to break all the bonds holding the particles in place
• Gaseous state


  • Particles are free to move and have large gaps between them
• As it is heated

  The particles vibrate more (solid), move past each other more quickly (liquid), move more quickly (gas)
• The energy used in melting is the specific latent heat of fusion
• The energy used in boiling is the specific latent heat of vaporisation, which is larger than the latent heat of fusion because more bonds are broken
• The SI unit of energy is the joule (J).
• Energy can be transferred as heat or work.
• Conduction - Heat transfers through direct contact between particles.
• Radiation - Energy travels through space without any medium.
• Convection - Hot air rises and cold air falls due to differences in density.
• Thermal insulators are materials that prevent heat transfer.