Answer:
X represents barium - 141 nucleus.
Written as: (141, 56) Ba
Step-by-step explanation:
In nuclear fission reaction, due to the fact that the process produces more neutrons, a nuclear chain reaction can possibly occurr. Now, a chain reaction is a one whereby the material that begins the reaction will also be one of the products and it can start another reaction.
Now, for the nuclear chain reaction for the fission of uranium-235, its nucleus absorbs a neutron after which it splits into a krypton - 92 nucleus and a barium - 141 nucleus. Thereafter it releases three more neutrons.
Thus, X is the image represents barium - 141 nucleus.
(141,56) Ba