What nuclide is necessary to balance the following fission reaction? U + n $\to$ 3 n + Ba + __________
A) Br
B) Kr
C) Rb
D) Kr
E) Sr

Question

What nuclide is necessary to balance the following fission reaction?  U +  n $\to$ 3  n +  Ba + __________
A) Br 
B) Kr 
C) Rb 
D) Kr 
E) Sr

Quizplus · Accepted Answer

In the given fission reaction, the uranium nucleus (with a mass of 235 and atomic number of 92) absorbs a neutron and undergoes fission to form two fission fragments and release some neutrons. We need to determine the identity of one of the fission fragments.

To do this, we can look at the conservation of mass and atomic number. The mass of the uranium nucleus plus the neutron equals the combined mass of the two fission fragments and the additional neutrons released. The atomic number (proton number) of the uranium nucleus plus the neutron must also equal the sum of the atomic numbers of the two fission fragments.

Using this information, we can determine that one of the fission fragments must have a mass of approximately 94 and an atomic number of approximately 36. The only answer choice that corresponds to a nuclide with these properties is D, which is 11 Kr 94.

What Nuclide Is Necessary to Balance the Following Fission Reaction →\to→

What Nuclide Is Necessary to Balance the Following Fission Reaction $\to$