Kaplan Nursing Entrance Practice Exam

The statement that is not true about the fusion reactions in the sun's core is that electrons are released during the reaction. In the process of nuclear fusion that occurs in the sun, hydrogen nuclei (protons) come together under extreme temperature and pressure to form helium nuclei. This process primarily involves the fusion of protons, where the protons essentially overcome their electrostatic repulsion due to the high energy conditions.

During these reactions, the protons themselves do not release electrons; instead, what happens is that two protons fuse to form a deuterium nucleus (a proton and a neutron), and in the process, a positron and a neutrino are emitted, not electrons. Therefore, the concept of electrons being released is inaccurate in the context of the fusion processes that occur in the sun's core.

In contrast, the other statements are accurate in describing aspects of nuclear fusion in the sun. The mass of the products being less than the mass of the reactants is consistent with the principle of mass-energy equivalence, which indicates that the "lost" mass is converted into energy, according to Einstein’s equation E=mc². The assertion that six photons are emitted relates to the energy produced during the fusion process, particularly in the chain of