Answer:
Because of the formula [tex]E=mc^2[/tex]
Explanation:
In this problem we are describing two different processes:
In both cases, the total mass of the final products is smaller than the total mass of the initial nuclei.
According to Einsten's formula, this mass difference has been converted into energy, as follows:
[tex]E=\Delta mc^2[/tex]
where:
E is the energy released in the reaction
[tex]\Delta m[/tex] is the mass defect, the difference between the final total mass and the initial total mass
[tex]c=3.0 \cdot 10^8 m/s[/tex] is the speed of light
From the formula, we see that the factor [tex]c^2[/tex] is a very large number, therefore even if the mass defect [tex]\Delta m[/tex] is very small, nuclear fusion and nuclear fission release huge amounts of energy.