Answer:
Nuclear fission
Step-by-step explanation:
Even though the equation is not too clear, however, we can see that the uranium nucleus was bombarded with a particle leading to its disintegration to yield other nuclides.
A nuclear fission reaction is one in which a heavier nuclide is bombarded with a particle (usually a neutron) leading to the disintegration of that nuclide into other nuclides with the release of tremendous energy. More neutrons are released in the process to continue the reaction. Hence, it is a chain reaction.