How can radiation be detected?

Radiation can be detected through various methods, and one effective way is by observing its effect on photographic film. When radiation, such as gamma rays or beta particles, hits the film, it fogs the film by causing a chemical change that results in a latent image. This change is due to the ionization of the silver halide crystals in the film emulsion, which becomes more sensitive to light. As a result, areas exposed to radiation will appear darker when developed, providing a visual indication of where radiation was present.

This method of detection is widely used in various fields, including medical imaging, radiation safety, and nuclear science, because it allows for the accurate measurement of radiation exposure and potential hazards. Other options mentioned do not offer reliable or consistent ways to detect radiation; therefore, the fogging of photographic film serves as a clear and practical method in recognizing the presence of radiation.