* Uranium-238 (²³⁸U): This is the most abundant isotope, accounting for about 99.27% of natural uranium. It's also the most stable isotope, with a half-life of 4.468 billion years.

* Uranium-235 (²³⁵U): This isotope is much less abundant, making up only about 0.72% of natural uranium. It's fissile, meaning it can sustain a nuclear chain reaction, and is used in nuclear power plants and weapons. It has a half-life of 703.8 million years.

* Uranium-234 (²³⁴U): This is the least abundant isotope, making up only about 0.0055% of natural uranium. It's also radioactive and has a half-life of 245,500 years.

There are also several synthetic isotopes of uranium, but these are not found in nature and are produced in nuclear reactors or accelerators. Some examples include:

* Uranium-233 (²³³U): This is a fissile isotope that is produced from thorium-232.

* Uranium-236 (²³⁶U): This is a non-fissile isotope that is produced in nuclear reactors.

Note: Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons. This difference in neutron number affects the atom's mass and its radioactive properties.