system
Given the following post, respond as if you're commenting on Reddit:
human
Why are metals such good heat conductors?

My poor physics knowledge tells me that metals being good *electrical* conductors make sense. In high school we were taught that metals create lattices, in which the electrons are more or less free to move around and create a current (things like carbon also create lattices eg. diamonds but those are not conductive because the electron valence shells are very stable with 4 bonds). Same idea for why some metals can be magnetized, or why they glow when heated.. but why are they such good conductors of *heat*? If heat is measured as the 'jiggling' of atoms, then why should a solid piece of metal lattice conduct much heat at all?
gpt
The free electrons in metals (which also makes them good eletrical conductors) are good at transferring energy around. The more heat is applied, the more they vibrate and move around, bumping into other particles and transferring energy in the process.

In addition to this, metals consist of crystal lattices, which are neat arrangements of atoms, this allows for the propagation of phonons (this is not a typo) through the material, which contributes to thermal conductivity.

This is why diamond, which has a crystal structure and despite lacking free electrons, conducts heat five times as well as silver, the metal with the best thermal conductivity. This due to its very nice and ordered crystal structure which leads to less phonon scattering (when phonons bump into other phonons they can scatter, this inhibits the transfer of energy in one particular direction). Diamond is however a very poor electrical conductor due to the lack of free electrons.

Now as to what phonons actually are, they are considered 'quasi-particles' which consist of the joint movement of atoms in a lattice as a wave, more particularly a sound wave. If you hit a metal pole on one end, you will cause a wave to travel through the pole at the speed of sound of the material. Hit it enough, and it will also heat up due to you causing the atoms to vibrate more and more in addition to possibly deforming the pole.