There's no diagram attached, but diffusion of heat within the water (which i think is what the question's asking) would be due to convection currents.
<u>Answer:</u> The nuclear fission reaction of U-234.043 is written below.
<u>Explanation:</u>
In a nuclear reaction, the total mass and total atomic number remains the same.
For the given fission reaction:

<u>To calculate A:</u>
Total mass on reactant side = total mass on product side
234.043 = 137.159 + A + 3(1.0087)
A = 93.858
Now, the chemical equation becomes:

Hence, the nuclear fission reaction of U-234.043 is written above.
Answer:
refer the above attachment