Transuranics

Part of speech: noun

Definitions

1. Elements that have atomic numbers higher than uranium, typically created artificially in nuclear reactors or laboratories
2. A category of radioactive elements that are not found in nature and include plutonium and americium
3. Substances that fall under the category of actinides, possessing unique properties and applications in fields such as nuclear energy and medicine

Etymology: Uranium is named after a planet. The German chemist Martin Heinrich Klaproth named the metal after Uranus, which had been discovered only shortly before. When scientists later made elements heavier than uranium, they kept the planetary theme: neptunium was named after Neptune, and plutonium after Pluto, the next planet out. The prefix "trans-" is Latin for "across" or "beyond," so this term simply means "beyond uranium." It is a plain descriptive formation, built from the prefix and the element's name, and it covers elements with atomic numbers above 92, the number of uranium's protons.