In the electromagnetic spectrum, frequency increases and wavelength decreases as you move from radio to gamma rays.

• A. Wavelength is constant.
• B. Frequency increases while wavelength decreases as you move from radio to gamma rays.
• C. Frequency and wavelength both increase.
• D. Frequency decreases while wavelength increases.

Answer: (B)

The key idea is that the speed of light in a vacuum is the same for all electromagnetic waves, so frequency and wavelength are inversely related. The basic relationship is f × λ = c, where c is about 3.00 × 10^8 m/s. Because c is constant, if frequency increases, wavelength must decrease.

As you move from radio to gamma rays, the frequency climbs from very low values to extremely high values, while the wavelengths shrink from long meters (or kilometers in some radio bands) to tiny picometers for gamma rays. So the statement that frequency increases while wavelength decreases as you move from radio to gamma rays is the correct description of how these two properties relate across the spectrum.

Wavelength being constant wouldn’t fit the spectrum, and both quantities increasing or frequency decreasing with increasing wavelength would contradict the observed progression from radio to gamma.