Here's why:
* Fissionability: Uranium-235 is fissile, meaning its nucleus can be split (fissioned) by absorbing a neutron, releasing a tremendous amount of energy.
* Abundance: While uranium-235 is only a small percentage of naturally occurring uranium (about 0.7%), it is still relatively abundant and can be extracted and enriched.
Other elements used in nuclear reactors:
* Plutonium-239: This element is also fissile and can be produced from uranium-238 in nuclear reactors.
* Thorium-232: While not directly fissile, thorium can be used in "thorium reactors" to produce uranium-233, which is fissile.
It's important to note that these elements are not directly "burned" like fossil fuels. Instead, their nuclei are split, releasing energy in the process.
