*
Visual science, temperature (16/40) Temperature is a measure of hotness, average kinetic energy per molecule in a substance, those atoms and molecules inside things don't stay still, even in a solid, they're constantly moving and jiggling, regions in thermal contact will have the same temperature when there is no net exchange of internal energy between them. Temperature then is what determines the direction of heat flow, out of the higher temperature region and into the lower temperature region, flowing from hot to cold based on any deficits. Kelvin is the SI unit of temperature!