In the role of microwave high frequency alternating electric field: The polar molecules in the reaction mixture participate in the dipole polarization effect: when the electric field oscillates, the molecular dipole tries to re-adjust itself along the alternating electric field lines, in the process, through molecular friction and dielectric loss (dielectric heating) Energy is lost in the form of heat. The charged particles in the mixture participate in the ion conduction process: they collide with adjacent molecules or atoms under the influence of the microwave field oscillating back and forth. These collisions cause intense movement and then generate heat.