Uranium-235 undergoes nuclear fission when its nucleus is split into two or more smaller nuclei. This process releases large amounts of energy, including gamma rays and free neutrons. The fission reaction also produces two to three smaller atomic nuclei, which are usually isotopes of elements like krypton, barium, strontium, or neodymium. These newly formed nuclei are lighter than uranium-235 and contain a significant amount of the remaining neutron mass and energy released in the fission process.

Here is a general representation of uranium-235 fission:

U-235 (nucleus) + neutron → fission fragments [e.g., Krypton (Kr-92) + Barium (Ba-141) or other combinations of lighter elements] + 2-3 neutrons + gamma rays + energy

It is important to note that the specific products and yields of fission reactions can vary based on individual uranium-235 fission events. While some reactions may produce the isotopes mentioned above, others might result in different combinations of elements depending on the nuclear pathways and energy distributions.