The quality, or penetrating power, of secondary radiation is:

Secondary radiation occurs when primary radiation interacts with matter, such as biological tissues or dental materials. This interaction causes the primary radiation to be absorbed and scattered, resulting in secondary radiation that typically has a lower energy and penetrating ability compared to the original primary radiation.

This reduced penetrating power occurs because secondary radiation is created from the original photons losing energy during interactions, which results in photons that are less capable of penetrating dense materials. Therefore, the quality of secondary radiation is generally less than that of the primary radiation it originates from.

Understanding this distinction is crucial in dental radiography, as it emphasizes the importance of optimizing exposure and minimizing unnecessary exposure to secondary radiation during imaging procedures.