Which wave has the highest frequency among infrared, microwave, ultraviolet, x-rays?

Which wave has the highest frequency among infrared, microwave, ultraviolet, x-rays?

• A. X-rays
• B. Infrared
• C. Microwave
• D. Ultraviolet

Answer: (A)

The key idea is that frequency and wavelength are inversely related in electromagnetic waves: shorter wavelengths mean higher frequencies (f = c/λ). Among these options, infrared and microwaves have longer wavelengths, ultraviolet is shorter but still longer than x-rays, and x-rays have the shortest wavelengths—on the order of tenths of a nanometer to a few nanometers. Because they’re shortest, x-rays have the highest frequency. This also means their photons have higher energy (E = hf) compared to the others. So, the wave with the highest frequency is x-rays.

The key idea is that frequency and wavelength are inversely related in electromagnetic waves: shorter wavelengths mean higher frequencies (f = c/λ). Among these options, infrared and microwaves have longer wavelengths, ultraviolet is shorter but still longer than x-rays, and x-rays have the shortest wavelengths—on the order of tenths of a nanometer to a few nanometers. Because they’re shortest, x-rays have the highest frequency. This also means their photons have higher energy (E = hf) compared to the others. So, the wave with the highest frequency is x-rays.