a chemical reaction is a rearrangement of atoms. The energy change accompanying chemical reaction is reflected in the difference of chemical bond energy between reactants and products, which is essentially the degree of bonding between extranuclear electrons and nuclei. The so-called mass defect means that the mass of each elementary particle is not conserved before and after the reaction in a nuclear reaction, which is a reaction within the nucleus, not a chemical reaction. They are essentially different, so how can we use the same model?

Therefore, learning must be clear about the basic concepts, and don't be ambiguous and specious. For the laws of physics, it is necessary to understand the essence, and don't blindly follow the formula. Otherwise, like a few brothers upstairs, after reading a few pages of Baidu Encyclopedia, they will come out and talk nonsense. Isn't it ridiculous?