Which has the longest (largest) wavelength?

### Radio waves

## Step1: Understanding Wavelength### Wavelength is the distance between successive crests of a wave, particularly in the context of electromagnetic waves such as light, radio waves, and microwaves.## Step2: Identifying Electromagnetic Spectrum### The electromagnetic spectrum is a continuum of all electromagnetic waves arranged according to frequency. It ranges from gamma rays with the shortest wavelength to radio waves with the longest wavelength.## Step3: Determining Longest Wavelength### Among the different types of electromagnetic waves, radio waves have the longest wavelength. They are followed by microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays in decreasing order of wavelength.