Molecular Conduction

Physics: Edexcel IGCSE, topic 4.4.3

How Conduction Happens

There are two mechanisms for conduction in a solid:

Lattice vibrations

Lattice vibrations

  • If one part of a solid is heated, the particles in that part gain energy and vibrate more.
  • These vibrations then transfer heat energy to neighbouring particles which also vibrate more.
  • The closer particles are together (in a more dense solid), the better the solid will conduct heat energy.
Electron transfer

Electron transfer

  • Metal lattices contain free (delocalised) electrons that can move anywhere in the lattice.
  • These electrons gain heat energy in the hot part of the object and carry it to other parts of the lattice.
  • Solids with more free electrons are better thermal conductors.

Test yourself on Molecular Conduction

  • Why do your feet feel colder on tiles than carpet?

  • Which of the following are true of conduction in metals?

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