Scatter radiation is defined as

• A. Results when an x-ray beam has been deflected from its path by interaction with matter.
• B. X-rays that come from the tube head.
• C. Radiation produced by computer monitors.
• D. Radiation from the sun.

Answer: (A)

Scatter radiation occurs when the primary x-ray beam interacts with matter and a photon is deflected from its original direction, often through Compton or Rayleigh scattering. The scattered photon travels in a different direction and can expose personnel or areas outside the intended image. This is why shielding and beam restriction are important in dental radiography. The other options describe radiation sources or types not involved in the scatter process: the primary beam comes from the tube head, computer monitors do not emit X-rays, and the sun’s radiation is unrelated to dental radiography.