What is the change called when x-rays, gamma rays, light, or electrons strike photographic emulsion?

When x-rays, gamma rays, light, or electrons strike photographic emulsion, the resulting change is known as a latent image. This process involves the interaction of radiation with the photographic emulsion, which consists of silver salts that become energized and undergo a chemical change upon exposure to radiation. However, this change is not immediately visible; it requires further development to transform the latent image into a visible one.

The term "latent" refers to something that is present but not yet visible. In the context of radiography, the latent image represents the unrevealed pattern of exposure that will later be developed into a visible image through chemical processing. This is a critical concept in radiographic testing, as understanding the nature of the latent image is essential for interpreting radiographs correctly.

The other terms do not accurately describe this process. A visible image refers to the final product after development, while shadow image and radiant image are not standard terms used in the context of photographic emulsion and radiographic imaging. Thus, the concept of a latent image is key to understanding how the radiographic process captures and eventually reveals the information contained in the initial exposure.