Which term refers to energy emitted in the form of rays or waves?

• A. Photons
• B. Light
• C. Radiation
• D. Sound

Answer: (C)

Energy emitted in the form of rays or waves is described as radiation. Radiation is the general term for energy that travels through space as electromagnetic waves or particles, covering a wide range from radio waves to gamma rays, and including visible light. Photons are the discrete energy packets that carry light energy, so they are related to radiation but do not define the broad process itself. Light refers specifically to the visible portion of electromagnetic radiation, not all forms of radiant energy. Sound is a different kind of energy—it travels as mechanical waves through a medium like air or water, not as electromagnetic radiation.