 Heat always flows from places of high heat to areas of lower heat

 Dynamic equilibrium- A balanced state  Energy will continue to transfer between objects until their energies are equal

 Radiation: The flow of energy as electromagnetic waves; How Earth receives solar energy.  Radiation is the only energy that can travel through space or through transparent/see-through materials

 Conduction allows energy to flow through the collision of the atoms or molecules- Most efficient in solids  Example: walking barefoot on hot ground  The air touching warm ground is also heated by conduction

 Convection distributes heat through fluids (liquids and gases)  Most materials expand when they are heated, which makes them less dense  Materials that are less dense tend to rise while denser material sinks  Convection cells: created by the differences in density  Examples: soup, wind, ocean currents, magma, and water