Subject: Why is sodium stable?

I appreciate the last answer but it really didn't get to the crux. I agree that it is easy to teach students with Lewis dots and tell that filling the shell is what atoms want to do but the students want to know why there are inconsistencies. I am not about to tell them just take my word on faith. I really try to introduce as much about the truth of science as I can. So the truth is that I am still confused. And once I can come to terms with this, I will feel better. Let me narrow the question down. Sodium has one electron in its valence shell. Now if the atom loses this electron its atomic radii decreases. This brings the electrons closer to the protons which seems to make a stable ion. In fact it would seem that this would be more stable than the neutral sodium ion which is much bigger. However energy is required to ionize sodium to this form! This suggests that the neutral sodium atom is more stable than the ion. What am I missing? What makes the neutral sodium stable? Conversely, Chlorine seems to be quite stable as a neutral atom. I can see this. It is smaller than when chlorine gains an electron. However chlorine is actually more stable when it gains an electron. The electron affinity energy stabilizes the chlorine ion. But why? The ion is bigger and the nuclear-outer shell interactions have been decreased! What I am missing? I am baffled. This is for my curiosity. Particularily, am I looking too much at atoms as particles. Please be clear that I not interested in the interaction between sodium and chlorine but the individual gaseous states of each and their independent energetics.

Re: Why is sodium stable?