PhysicsRankPREVIEWTry a problem

THE PRACTICE STUDIO

Go slowly. Ask why. Make it yours.

PRACTICE · MEMBERSIntermediate · Single correct

PRACTICE / Energy balance in nuclear reactions

Compare complete mass totals

For a hypothetical reaction with every particle included, the total initial nuclear rest mass is 20.040 u and the total final nuclear rest mass is 20.025 u. Use 1 u c² = 930 MeV.

Find the reaction Q value.

Organize the givens & assumptions
  • Initial mass sum = 20.040 u
  • Final mass sum = 20.025 u
  • 1 u c² = 930 MeV

Both totals use the same bare-nucleus/particle mass convention; no omitted products or electron-mass corrections.

  1. A+27.90 MeV+27.90\ \mathrm{MeV}
  2. B+13.95 MeV+13.95\ \mathrm{MeV}
  3. C−13.95 MeV-13.95\ \mathrm{MeV}
  4. D+0.015 MeV+0.015\ \mathrm{MeV}

Try it on paper first. Free sample problems in every collection include the complete reasoning: find one in this collection →