UNICAMP 2020

Nuclear fusion is a reaction in which atomic nuclei merge to form the nucleus of a new atom. The mass of the new atom’s nucleus is lower than the sum of the merging nuclei’s masses, a difference that is released as energy. This is, for instance, the reaction that occurs in the Sun. The energy released during fusion can be calculated by the equation E = Δmc² , where Δm is the difference between the initial and final masses in the reaction, and c is the speed of light. When calculating the aforementioned energy, nucleus mass can be conveniently quantified using the atomic mass unit (u), which is roughly equivalent to 900 MeV (1 u → 900 MeV). Consider the hypothetical nuclear fusion reaction ²²²X + ⁴Y → ²²¹Z. Note that the masses of ²²²X, ⁴Y, and ²²¹Z are 222 u, 4 u, and 221 u, respectively.

The amount of energy released in this reaction is