thermal conduction Flashcards
thermal conduction is the main method of energy transfer in what?
solids
when does conduction occur?
2 solids of different temperatures come into contact with one another and energy is transferred through the vibration of atoms within solids- energy is transferred from the thermal store of the hotter object to the cooler object
what happens when one particle vibrates?
when one particle vibrates it bumps into a neighbouring particle and causes that to vibrate- transferring energy between the kinetic stores of the particles
the closer the particles…
the faster thermal conduction takes place
what are the best thermal conductors?
metals
why are metals the best thermal conductors?
the delocalised electrons colliding with the atoms- help to transfer the vibration through the material- therefore, transfer heat better
what are poor thermal conductors?
non- metals
are liquids and gases good thermal conductors?
no- they are extremely poor
why are materials that contain small pockets of trapped air good insulators?
air is a gas therefore a poor conductor
what does the air being trapped do?
the air is trapped and so cannot move and form a convection current- therefore energy transfer by conduction occurs but very slowly
what happens when a substance is heated?
the atoms start to vibrate more- they bump into eachother- transferring energy from atom to atom
