Question

In fission of one uranium-235 nucleus, the loss in mass is 0.2 amu. Calculate the energy released.

• A. 186.2 MeV
• B. 182.6 MeV
• C. 156.4 MeV
• D. 189.1 MeV

Answer 1

The correct option is A

186.2 MeV

Step 1: Given data

Mass defect $∆\mathrm{m}=0.2\mathrm{amu}$

Energy equivalent of 1 amu is 931MeV.

Step 2: Calculation of the energy released

From Einstein mass-energy relation:

$$\begin{gathered} \mathrm{Energy}\mathrm{released}=\mathrm{mass}\mathrm{defect}\times \mathrm{speed}\mathrm{of}{\mathrm{light}}^2 \\ \mathrm{E}=∆\mathrm{m}\times {\mathrm{c}}^2 \\ \mathrm{E}=0.2\times 931\mathrm{MeV} \\ \mathrm{E}=186.2\mathrm{MeV} \end{gathered}$$

So the energy released is 186.2MeV. Thus A is the correct option.