In a fission reaction, uranium-235 bombarded with a neutron produces strontium-94, another small nucleus, and 3 neutrons. Write the nuclear equation for this reaction.

Answer 1

The first numeber is the atomic number followed by the element symbol followed by the mass number; thus 26Co60 is Co 60 (Co is element 26).
92U235 + 0n1 ==> 38Sr94 + yXz + 3 0n1
Atomic numbers must add up.
Mass numbers must add up. Therefore,
92 + 0 = 38 + y + 0. Solve for y = 54 and element 54 is Xe.
Then 235 + 1 = 94 + z + 3 and z = 138
Rxn is
92U235 + 0n1 ==> 38Sr94 + 54Xe138 + 3 0n1

Answer 2

that should be 54Xe139, not 138