The atomic mass of C 12 6 is 12 . 000000u and that of C 13 6 is 13...

Given the nuclear reaction is

$C 13 6 + Energy \to C 12 6 + n 1 0$

The mass defect for the above reaction can be calculated as follows:

$\begin{cases}\Deltam & = & \left[( 12 . 000000 + 1 . 008665 ) - 13 . 003354\right]u \\ & = & - 0 . 00531u\end{cases}$

Hence, the energy required is given by

$\begin{cases}E & = & 0 . 00531 \times 931 . 5MeV \\ & = & 4 . 95MeV\end{cases}$