The term describing the degree of blackening in a radiograph due to the accumulation of black metallic silver is known as:

The degree of blackening in a radiograph, which results from the accumulation of black metallic silver, is termed density. This concept is fundamental in radiography as it reflects how much radiation is absorbed by the film or sensor. High-density areas appear darker on the radiograph because they have a greater amount of exposed silver, indicating that the tissues in that area absorbed less radiation and thus more silver was developed.

Density is crucial for interpreting radiographs, as it directly affects the visibility of structures within the image; it highlights the differences in tissue composition and pathology. Understanding this concept helps radiographers and technicians optimize exposure factors and processing techniques to achieve the best diagnostic quality in images.

Image media refers to the various materials used to capture images, such as film or digital sensors, but does not specifically address the concept of blackening. Shade of contrast relates to the differences in density throughout the image but does not define the term itself. Brightness is related to how light or dark an image appears, which can be influenced by display settings but does not accurately describe the intrinsic quality or quantity of blackening due to silver accumulation in the radiographic process.