Final answer:
The forms of light in the electromagnetic spectrum, ordered by increasing frequency, are radio waves, infrared, visible light, ultraviolet, X-rays, and gamma rays. Higher frequency corresponds to shorter wavelengths and more energy per photon.
Step-by-step explanation:
The electromagnetic spectrum consists of various forms of light that are defined by their frequencies and wavelengths. When ranking these forms of light by increasing frequency, we start with the lowest frequency and end with the highest. Accordingly, the correct order from lowest to highest frequency is radio waves, infrared, visible light, ultraviolet, X-rays, and gamma rays. Remember that frequency and wavelength are inversely related; types of light with higher frequency have shorter wavelengths, and they also contain more energy per photon.