Which type of electromagnetic radiation has the longest wavelength?

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

Answer: (C)

Verified step by step guidance

1. Recall that electromagnetic radiation is arranged in the electromagnetic spectrum according to wavelength and frequency.
2. Understand that wavelength (\( \lambda \)) and frequency (\( \nu \)) are inversely related by the equation: \[ \lambda = \frac{c}{\nu} \] where \( c \) is the speed of light.
3. Identify the types of electromagnetic radiation given: Ultraviolet light, Gamma rays, Radio waves, and X-rays.
4. Know the general order of electromagnetic waves from shortest to longest wavelength: Gamma rays, X-rays, Ultraviolet light, Visible light, Infrared, Microwaves, Radio waves.
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.