## Question

In a thermonuclear reaction the total initial mass is 5.02 x 10^{-27} kg and the total final mass is 5.01 x 10^{-27} kg. What is the energy released in the process? [c = 3 x 10^{8} m/s]

### Answer

**Data:** Initial mass, m_{1} = 5.02 x 10^{-27} kg, Final mass, m_{2} = 5.01 x 10^{-27} kg, c = 3 x 10^{8} m/s

Mass defect m = initial mass – final mass

m = m_{1} – m_{2} = 5.02 x 10^{-27} – 5.01 x 10^{-27} = 1.0 x 10^{-29} kg

Energy released, E = mc^{2} = 1.0 x 10^{-29} x (3 x 10^{8})^{2} = 1.0 x 10^{-29} x 9 x 10^{16} = 9.0 x 10^{-13} Joule

E = 9.0 x 10^{-13} Joule