There are three main methods of heat transfer. conduction, convention and radiation! conduction and convention both involve particles but radiation travels using electro magnetic waves!!!

Conduction

This is where heat energy passes through a substaance. Metals are good conductors of heat, whereas non-metals and gasses are bad conductors of heat. Heat travels from a warm part of an object to the cold part of the object!!!

All particles are made up of ions. when the atom loses/frees some of the electrons the ions become charged. Ihe ions are compressed together  and are constantly vibrating. the hotter one part of the metal is the more kenetic energy the vibrations have. the vibrations pass on from one part of the metal to the other! the more kenetic energy the vibrations has the hotter the ions get. The kenetic energy from the vibrations is passed on using the free electrons which move in around in the metal structure.

Convention

Heat energy is transfered from one place to another using convection! convection takes place in fluids which are either a liquid of a gas.  convecion occurs when alot of heat energy from a liquid or gas takes the place of The particles with less heat energy!!! a useful fact is that liquids and gasses expand when they are hot. this is however not because of the particles are getting bigger but because the gaps inbetween the particles are getting bigger.Did you also know that because of a liquid or gas in hot areas is less dense than a liquid or gas in cold areas the cold liquid or gas falls into the warmer areas and the hotter liquid or gas rises into the cold areas. this is how convection currents are set up!!!



Radiation

Thermal radiation is also called infra red radiation.  the hotter an object is the more infra red rays it produces. unlike conjvecton and conduction, infra red radiation ( which is a type of infra red radiation) does not involve particles. just waves. this is why the sun's rays can travel through the vacuum in space. This shows just how hot the sun is as it is able to emit such powerful waves that would reach the earth which is 150 million KM away!!!

Some surfaces are alot better at absorbing and reflecting the infra red waves.A results table shows that darker colours absorbe the waves alot better than light colours!!!


Did you know that if you put two objects, one fat, and one long and thin that are exacly the same colour, the long thin one woud absorb ad reflect the most waves. This is why radiators ar long thin and painted white. Although despite their name radiators do not radiate heat usualy they use convection to transfer their heat.