The range of electromagnetic waves placed in a certain order is called the

Depends on the order. If in the order of wavelength, or frequency, or energy in each photon, then it's the electromagnetic spectrum. If, say, alphabetical order, then it would be something else.

The electromagnetic spectrum is the complete range of electromagnetic waves placed in order of increasing frequency. The electromagnetic spectrum is made up of radio waves, infrared rays, visible light, ultraviolet rays, X-rays, and gamma rays