Nuclear mass–energy equivalence: numerically, 1 atomic mass unit (1 amu) corresponds to approximately how much energy?

Introduction:Converting between atomic mass units and energy is routine in nuclear physics and engineering. The amu-to-MeV conversion arises from E = m * c^2, enabling quick estimation of reaction Q-values and binding energies.

Given Data / Assumptions:

• Use the widely accepted conversion: 1 u ≈ 931.5 MeV (often rounded to 931 MeV in MCQs).
• We need only the order-of-magnitude and correct unit.

Concept / Approach:The rest energy corresponding to 1 atomic mass unit is about 931.5 MeV. In multiple-choice contexts, 931 MeV is the standard rounded value. This conversion is essential for analyzing nuclear reactions and decay energetics without detailed SI calculations.

Step-by-Step Solution:Recall: 1 u ≈ 1.6605 × 10^-27 kg.Compute energy using E = m * c^2 → ≈ 1.4924 × 10^-10 J.Convert joules to eV (1 eV = 1.602 × 10^-19 J) → ≈ 9.315 × 10^8 eV ≈ 931 MeV.

Verification / Alternative check:Standard nuclear data tables list 1 u ≈ 931.494 MeV, confirming the rounded figure.

Why Other Options Are Wrong:

• 9.31 MeV or 931 eV: off by two or six orders of magnitude, respectively.
• 931 J: incorrect unit; the energy scale in nuclear physics is MeV, not joules for quick tabulations.
• 93.1 keV: off by a factor of 10,000.

Common Pitfalls:Mistaking eV, keV, MeV prefixes or mixing energy in eV with mass in amu without proper conversion.

Final Answer:931 MeV