Radioactive particle is a term used to describe an atom that has an unstable nucleus and can emit radiation as it decays. There are several synonyms for this term, including radioactive atom, radiating element, isotope, and radioactive material. Radioactive isotopes can come in different forms, depending on the number of protons and neutrons in their nuclei. Some of the most common isotopes include carbon-14, uranium-235, and iodine-131. These radioactive particles can have a variety of applications, from medical imaging to nuclear power generation. However, they can also pose a danger to human health if not handled properly, which is why proper containment and disposal is essential.