Arrange radio, infrared, and X-ray from longest to shortest wavelength. There is exactly one right order, and it never changes.
The spectrum's bands keep fixed places. Learn the scale once, and every ordering question becomes a walk along it.
Here is the whole scale, from long wavelengths to short: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, gamma rays.
Radio waves hold the long-wavelength end of the scale.
Gamma rays hold the short-wavelength end.
Every other band keeps its one fixed place between them.
Take radio, infrared, and X-ray: from longest to shortest wavelength, the order reads radio waves, infrared, X-rays.
Asked shortest first, read the same scale the other way.
Order ultraviolet, radio waves, and visible light from longest to shortest wavelength.
Place them on the scale: radio waves at the long end, visible light in the middle stretch, ultraviolet just past visible toward the short end.
Read them off from the long end.
Radio waves, visible light, ultraviolet.
Order gamma rays, infrared, and microwaves from shortest to longest wavelength.
Place them: gamma rays at the short end, infrared between visible light and microwaves, microwaves next to radio waves.
Read the scale from the short end.
Gamma rays, infrared, microwaves.
Which list orders microwaves, visible light, and X-rays from longest to shortest wavelength?
Which list orders radio waves, ultraviolet, and infrared from shortest to longest wavelength?
Of infrared, microwaves, and gamma rays, which has the shortest wavelength?
Which list orders radio waves, X-rays, visible light, and infrared from longest to shortest wavelength?
Of ultraviolet, microwaves, visible light, and gamma rays, which has the longest wavelength?
Four students each wrote the spectrum's bands in order of decreasing wavelength. Which list is correct?