Final answer:
Energy released in nuclear reactions is calculated using Einstein's equation, with free energy such as Gibbs free energy used to compare different chemical reactions. Activation energy can be visualized on a reaction coordinate diagram.
Step-by-step explanation:
To calculate the energy released during mass destruction in a nuclear reaction such as fission or fusion, Einstein's equation E=mc2 is used, where 'E' is energy, 'm' is the mass loss, and 'c' is the speed of light. This equation establishes that mass can be converted into energy, and vice versa, which explains the large amount of energy produced in these processes. The energy-storing bonds break during these nuclear reactions, resulting in a slight mass loss and release of a significant amount of energy. Comparing the free energy of different reactions, such as chemical or nuclear, involves measuring the Gibbs free energy changes, which provide a way to quantify usable energy post the consideration of entropy. In the case of chemical reactions, the reaction coordinate diagram helps visualize the difference in energy between the reactants and the activated complex, reflecting the activation energy.