Which type of electromagnetic radiation has the longest wavelength?

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

Answer: (A)

Verified step by step guidance

1. Recall the electromagnetic spectrum, which arranges types of electromagnetic radiation by their 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 (approximately \( 3.00 \times 10^{8} \, \text{m/s} \)).
3. Identify the types of electromagnetic radiation given: radio waves, X-rays, ultraviolet light, and visible light.
4. Recall the general order of electromagnetic radiation from longest to shortest wavelength: radio waves > visible light > ultraviolet light > X-rays.
5. Conclude that among the options, radio waves have the longest wavelength because they have the lowest frequency and thus the largest \( \lambda \) according to the inverse relationship.