Which form of electromagnetic radiation has the longest wavelength?

• A. Ultraviolet light
• B. Radio waves
• C. Gamma rays
• D. X-rays

Answer: (B)

Verified step by step guidance

1. Recall the electromagnetic spectrum, which arranges types of electromagnetic radiation by their wavelength or frequency.
2. Understand that wavelength and frequency are inversely related by the equation \(\lambda = \frac{c}{\nu}\), where \(\lambda\) is wavelength, \(c\) is the speed of light, and \(\nu\) is frequency.
3. Identify the relative positions of the given types of radiation on the electromagnetic spectrum: Gamma rays, X-rays, Ultraviolet light, and Radio waves.
4. Recognize that Gamma rays have the shortest wavelengths and highest frequencies, followed by X-rays, then Ultraviolet light, and finally Radio waves, which have the longest wavelengths and lowest frequencies.
5. Conclude that among the options, Radio waves have the longest wavelength because they are located at the low-frequency, long-wavelength end of the electromagnetic spectrum.