Question

which wave has the longest wavelength?

Explanation:

Step1: Recall the electromagnetic spectrum

The electromagnetic spectrum (from longest to shortest wavelength) is: Radio waves, Microwaves, Infrared, Visible light, Ultraviolet, X - rays, Gamma rays.

Step2: Compare the given options

Among Visible Light, X - Rays, Infrared, and Radio, Radio has the longest wavelength according to the order of the electromagnetic spectrum.

Answer:

Radio