The electromagnetic spectrum goes in order from least energetic to most energetic or the other way around. If you were looking at the electromagnetic spectrum as least to most Hz, the order of the electromagnetic spectrum goes from radio and television waves being least energetic, microwaves just after the radio and television waves, infra-red radiation being 5th most energetic, then to visible light being forth most, ultraviolet light being thirdly most energetic and then finally, x-rays and then gamma rays being the most energetic. (Look above for diagram)