Which of the following is an example of non-ionizing radiation?

Non-ionizing radiation refers to types of radiation that do not carry enough energy to ionize atoms or molecules, meaning they cannot remove electrons from atoms. This category includes various forms of electromagnetic radiation that have longer wavelengths and lower energy levels than ionizing radiation.

Visible light is an excellent example of non-ionizing radiation. It falls within the spectrum of electromagnetic radiation that is detectable by the human eye and is commonly encountered in everyday life. It does not have the energy to cause ionization; rather, it interacts with matter through processes such as absorption and reflection without displacing electrons.

In contrast, alpha particles, X-rays, and gamma rays are types of ionizing radiation. Alpha particles are massive and positively charged particles that can cause significant ionization in the materials they interact with. X-rays and gamma rays, which are both forms of high-energy electromagnetic radiation, have enough energy to ionize atoms and are widely used in medical imaging and treatment, showcasing their capability to displace electrons from atoms.

By understanding these distinctions, it becomes clear why visible light is classified as non-ionizing radiation, while the other options represent forms of radiation that can lead to ionization.