The radioactive atoms that result from fissioning are called

• A. Radioactive isotopes
• B. Activation products
• C. Transuranics
• D. Fission products

Answer: (D)

When a heavy nucleus splits, the pieces it breaks into are called fission fragments, and together they’re known as fission products. These fragments are typically radioactive right after fission because they have neutron-rich configurations and undergo beta decay toward stability, emitting radiation as they transform into more stable atoms. That decay can produce heat and radiation long after the fission event.

The other terms describe different concepts. Radioactive isotopes is a broad label for any radioactive form of an element, not specifically tied to fission. Activation products are created when materials become radioactive due to exposure to neutrons or other radiation, not the direct fission fragments themselves. Transuranics are elements with atomic numbers greater than uranium, formed in reactors through neutron capture and subsequent decays, and aren’t the generic products of fission. So the entities produced by fission are best described as fission products.