Which statement correctly describes UV light compared to infrared light?

• A. UV light has smaller wavelengths than infrared light.
• B. UV light has larger wavelengths than infrared light.
• C. UV and infrared have similar wavelengths.
• D. Infrared light has smaller wavelengths than UV.

Answer: (A)

Wavelength and energy are inversely related along the electromagnetic spectrum. Ultraviolet light sits to the side of the visible range with shorter wavelengths, while infrared light lies on the longer-wavelength side. In approximate terms, UV spans about 10 to 400 nanometers, and infrared covers roughly 700 nanometers up to a millimeter. Because photon energy is E = h c / λ, shorter wavelengths mean higher energy per photon. Therefore, UV light has smaller wavelengths than infrared light, making the statement accurate. The idea that UV would have larger wavelengths, or that UV and infrared are similar in wavelength, contradicts how the spectrum is arranged.