Radio waves are described as

Radio waves are described as

• A. Ionizing radiation used in CT
• B. Nonionizing electromagnetic radiation (eg MRI)
• C. High-energy particles
• D. Visible light used in photography

Answer: (B)

Radio waves are a form of electromagnetic radiation with long wavelengths and very low energy per photon, which means they do not have enough energy to remove electrons from atoms. Because of this, they are classified as nonionizing electromagnetic radiation. In MRI, nonionizing radiofrequency pulses are used to disturb the alignment of hydrogen nuclei in a strong magnetic field and then detect the signals that result, all without ionizing the tissue. The other descriptions don’t fit radio waves: ionizing radiation like X-rays (used in CT) has much higher energy per photon and can ionize atoms; high-energy particles are not electromagnetic waves at all, but particles such as protons or electrons; visible light belongs to a higher-frequency part of the spectrum and is not what radio waves refer to.

Radio waves are a form of electromagnetic radiation with long wavelengths and very low energy per photon, which means they do not have enough energy to remove electrons from atoms. Because of this, they are classified as nonionizing electromagnetic radiation. In MRI, nonionizing radiofrequency pulses are used to disturb the alignment of hydrogen nuclei in a strong magnetic field and then detect the signals that result, all without ionizing the tissue.

The other descriptions don’t fit radio waves: ionizing radiation like X-rays (used in CT) has much higher energy per photon and can ionize atoms; high-energy particles are not electromagnetic waves at all, but particles such as protons or electrons; visible light belongs to a higher-frequency part of the spectrum and is not what radio waves refer to.