The fusion reaction of hydrogen atoms to form helium atoms is known as nuclear fusion, which occurs in the core of the Sun and other stars. In this process, four hydrogen nuclei protons combine to form one helium nucleus two protons and two neutrons with the release of a large amount of energy. The overall reaction can be represented as:4 H-1 4 protons He-4 2 protons + 2 neutrons + 2 e+ + 2 _e + energyHere, e+ represents a positron, and _e represents an electron neutrino.To calculate the standard enthalpy change for this reaction, we need to consider the mass difference between the reactants and products, which is converted into energy according to Einstein's famous equation, E=mc.Mass of 4 H-1 atoms = 4 1.007825 amu = 4.0313 amuMass of 1 He-4 atom = 4.001506 amuMass difference m = 4.0313 amu - 4.001506 amu = 0.029794 amuTo convert the mass difference into energy, we need to convert amu atomic mass units to kg and then use the E=mc equation.1 amu = 1.66054 10^-27 kgm = 0.029794 amu 1.66054 10^-27 kg/amu = 4.9509 10^-29 kgNow, we can calculate the energy released using E=mc:E = 4.9509 10^-29 kg 3.00 10^8 m/s E = 4.4558 10^-12 JSince this is the energy released for one reaction, we need to find the energy per mole of reactions. There are 6.022 10^23 particles in one mole, so:Energy per mole = 4.4558 10^-12 J 6.022 10^23Energy per mole = 2.681 10^12 J/molThe standard enthalpy change for the fusion reaction of hydrogen atoms to form helium atoms is approximately +2.681 10^12 J/mol. The positive sign indicates that the reaction is exothermic, meaning it releases energy.