I would like to know if there is any difference between the binding energy of a nucleus and the binding energy of an atom and what exactly do we mean when we say Binding energy per nucleon..
Edit to the Comment below: So I am currently studying a course in Nuclear physics and the concept of Binding energy comes up when we are discussing ways of calculating the charge and matter distribution inside the nucleus. So, we use scattering experiments to work out the distribution of protons and neutrons inside the nucleus and based on that we defined the binding energy of an atom to be the mass deficit multiplied by $c^2$. But then later on when we were deriving the semi empirical mass formula we suddenly started called $M(Z,A)$ as the binding energy of the nucleus which is why I was wondering what the difference was. And with regards to the binding energy per nucleon, I wanted to know whether the binding energy per nucleon is the same as binding energy of the nucleus or not