On the periodic table, uranium is the element whose atoms have 92 protons.
Atomic number 92 defines uranium, whose chemical symbol is U. It is a naturally occurring actinide and the heaviest element found in significant quantities in nature. Uranium has several isotopes, including uranium-238 and uranium-235, which differ in neutron number.
Uranium-235 is fissile, meaning it can sustain a nuclear fission chain reaction under suitable conditions. Uranium-238 is more abundant in natural uranium and can ultimately produce plutonium-239 after neutron capture and radioactive decay. These properties make uranium important in nuclear energy and weapons history.
The name comes from the planet Uranus, but uranium is not the element named after that planet in this question’s wording: the direct answer is the element itself. A common confusion is treating atomic number as atomic mass; uranium’s atomic number is 92, while its isotopes have mass numbers such as 235 and 238.