Which ionizing radiation source is commonly used in industry?

Cobalt-60 is commonly used in industry primarily due to its applications in radiotherapy and industrial radiography. This isotope emits gamma rays, which are useful for both medical treatments, such as cancer therapy, and for non-destructive testing in industrial applications. In radiography, Cobalt-60 is utilized to inspect welds and structural components for integrity without damaging them, making it a vital tool for quality control in manufacturing and infrastructure maintenance.

In contrast, the other options, while they involve ionizing radiation, are more specialized or used in different contexts. Uranium-238 is primarily associated with nuclear reactors and the production of nuclear fuel rather than routine industrial applications. Carbon-14 is widely used in archaeological dating but is not as relevant in industrial settings. Radon-222, although a significant source of natural ionizing radiation, is typically a concern in health and safety rather than an active tool in industry. This distinction highlights why Cobalt-60 stands out as a key isotope in industrial practices.