Solution
Energy, E = 10–3  × ( 3 × 108)2 J
     E = 10–3 × 9 × 1016 = 9 × 1013 J
Thus, if one gram of matter is converted to energy, there is a release
of enormous amount of energy Experimental verification of the Einstein’s mass-energy relation has
been achieved in the study of nuclear reactions amongst nucleons, nuclei,
electrons and other more recently discovered particles In a reaction the
conservation law of energy states that the initial energy and the final
energy are equal provided the energy associated with mass is also
included This concept is important in understanding nuclear masses
and the interaction of nuclei with one another