Which of the following differentiates ionizing from non-ionizing radiation and gives two examples of each?

• A. Ionizing radiations have enough energy to ionize atoms (examples: X-ray, gamma); non-ionizing do not (examples: UV, microwaves).
• B. Ionizing radiations have enough energy to ionize atoms (examples: UV, microwaves); non-ionizing do not (examples: X-ray, gamma).
• C. Ionizing radiations include visible light.
• D. Non-ionizing radiations include X-ray.

Answer: (A)

What differentiates ionizing from non-ionizing radiation is the energy per photon and whether that energy is sufficient to remove electrons from atoms. Ionizing radiation has photons energetic enough to ionize atoms, meaning it can eject electrons and create ions and free radicals; this is why X-rays and gamma rays are classic examples—they carry keV to MeV energies that readily overcome atomic binding energies. Non-ionizing radiation, on the other hand, does not have enough energy to ionize atoms, so its interactions with matter are typically through heating or molecular excitation rather than producing ions. In common classifications, UV radiation and microwaves are non-ionizing because their photons generally lack the energy to ionize most atoms.

So the correct statement identifies the key distinction correctly and pairs it with representative examples: X-ray and gamma rays as ionizing, UV and microwaves as non-ionizing. The other choices mix up which types of radiation ionize (for example, UV or X-ray being labeled incorrectly) or include a type like visible light as ionizing, which it is not in typical biological and medical contexts.