The chemical symbol for uranium is U.
Uranium is element 92 on the periodic table and belongs to the actinide series. Its symbol comes from the element’s English name, uranium, rather than from a Latin name. Chemical symbols are conventionally one or two letters, with the first letter capitalized and any second letter lowercase; uranium therefore uses the single capital letter U.
The element was identified in 1789 by German chemist Martin Heinrich Klaproth, who named it after the recently discovered planet Uranus. Metallic uranium was not isolated until 1841, when Eugène-Melchior Péligot produced it in a purer form. Uranium is naturally radioactive, and its isotopes have played important roles in nuclear science and radiometric dating.
The distractors are symbols for different elements: Th is thorium, Rn is radon, and Pu is plutonium. Uranium’s atomic number is 92, while its best-known naturally occurring isotopes are uranium-238 and uranium-235.