Which of the following correctly describes the nuclear composition of uranium-235?

• A. 235 protons, 0 neutrons
• B. 92 protons, 143 neutrons
• C. 92 protons, 142 neutrons
• D. 143 protons, 92 neutrons

Answer: (B)

Verified step by step guidance

1. Understand that the nuclear composition of an isotope is described by the number of protons and neutrons in its nucleus.
2. Recall that the atomic number (number of protons) for uranium (U) is 92, which is constant for all uranium isotopes.
3. Recognize that the mass number (A) is the sum of protons and neutrons: \(A = Z + N\), where \(Z\) is protons and \(N\) is neutrons.
4. Given uranium-235, the mass number \(A\) is 235, and the number of protons \(Z\) is 92, so calculate neutrons as \(N = A - Z = 235 - 92\).
5. Conclude that uranium-235 has 92 protons and 143 neutrons, matching the correct description of its nuclear composition.