Heat moves through liquid and circulates due to density a. radiation b. conduction c. convection d. water cycle a. radiation when the electromagnetic radiation in a region of space is at equilibrium with its surroundings, it can be described by the planck radiation formula. [ the total energy radiated from an area in this region of space is given by the stefan-boltzmann law and the energy density associated with the radiation can be related to that law. in the development of the expression for the