Respuesta :
Among the choices, the correct answer is A. According to Einstein's equation E = mc^2, the mass of an atomic nucleus as compared to its individual components is lesser. The missing mass is called mass defect. The missing mass happens because in the fusion process, some of the matter is turned into binding energy.
When a neutron and a proton combine to form a nucleus, the nucleus has less mass, because matter is converted into binding energy.
What is binding energy?
Binding energy is the amount of energy required to form the nucleus from the free protons and neutrons.
The binding energy results in a loss in mass of the free protons and neutrons as some mass is converted to energy.
Therefore, when a neutron and a proton combine to form a nucleus, the nucleus has less mass, because matter is converted into binding energy.
Learn more about binding energy at: https://brainly.com/question/15582431
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