In the nuclear fission reaction n + 235U → 92Kr + 141Ba + 3n, which of the following is the atomic mass (x) of krypton (Kr) produced?

• A. 3
• B. 141
• C. 92
• D. 235

Answer: (C)

Verified step by step guidance

1. Identify the given nuclear fission reaction: \(n + {}^{235}U \rightarrow {}^{x}Kr + {}^{141}Ba + 3n\).
2. Recall that in a nuclear reaction, both the total atomic number (number of protons) and the total mass number (number of protons + neutrons) are conserved.
3. Use conservation of mass number: The sum of the mass numbers on the left side must equal the sum on the right side. On the left, the mass numbers are \$1\( (for the neutron) and \)235\( (for uranium), totaling \)236$.
4. On the right side, the mass numbers are \(x\) (for krypton), \$141\( (for barium), and \)3 \times 1 = 3\( (for the three neutrons). Set up the equation: \)236 = x + 141 + 3$.
5. Solve for \(x\) by rearranging the equation: \(x = 236 - 141 - 3\). This value of \(x\) is the atomic mass number of krypton produced.