Final answer:
Uranium-235 is ideal for nuclear reactors due to its fissionability.
Step-by-step explanation:
Uranium-235 is considered ideal for nuclear reactors due to its fissionability. When uranium-235 atoms are split, they emit heat, high-energy radiation, and enough neutrons to maintain a chain reaction and provide energy to power a nuclear power plant. This is why uranium-235 is the preferred nuclear fuel.