P1.1 Heat Transfer

  • Created by: Fiona S
  • Created on: 11-06-15 20:31

Particle Structure


  • Tightly packed in a regular pattern
  • Particles have low energy
  • Their only movement is vibrating about their fixed positions


  • Particles are less tightly packed and can move around eachother
  • As the particles move more they have more energy than the particles in the solid


  • Particles are spread out with large spaces between them
  • Particles can move in all directions
  • So they have lots of energy


Slow Method - All solids

  • Particles which are heated gain energy
  • This means they vibrate more
  • They pass on increased vibrations to their neighbouring particles

Fast Method - Metals only

  • Metals contain free electrons  which can move freely throughout the metal
  • When the metal is heated the free electrons gain energy
  • They pass the energy on by colliding with another particle


Convection is a heat transfer that occurs in fluids. A fluid can be a gas or a liquid.


  • The particles in the part of the fluid which is heated gain energy and they move around more/vibrate more
  • This means they spread out and the warm fluid becomes less dense
  • The warmer fluid rises and colder, more dense fluid takes its place
  • This process repeats forming a convection current

Convection cannot occur in solids because the particles are fixed and unable to move past each other. 


  • Between the Earth and the Sun there is a vacuum
  • In that vacuum there are no particles
  • So heat transfer by Conduction or Convection is not possible
  • Heat is instead transferred by radiation
  • Radiation as an electromagnetic wave
  • All objects give off (emit) radiation
  • The hotter an object is the radiation it emits
  • All objects take in (absorb) radiation

dull, black surface is the best at absorbing radiation

shiny, silver surface is the best at reflecting radiation

Evaporation and Condensation


Evaporation is a process of when a liquid turns into a gas/vapour

Factors affecting the rate of evaporation

  • Increasing the surface area of the liquid
  • Increasing the temperature of the liquid
  • Creating a…


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