As a layperson...(Who is trying to understand the atom in a bit more detail). In the past, I have most often seen the atoms drawn with electron clouds that have bands of varying density. I understand the density of the bands represent areas of higher probability. I have often seen models of atoms drawn with clouds which are most dense near the nucleus with decreasing density as the radius increases. Question: Is there actually an intuitive way of understanding WHY atoms have these bands of higher probability? Is there an intuitive reason why the cloud is "thicker" in some areas/bands/distances from the nucleus? Is there a mathematical reason why the cloud is "thicker" in some areas/bands/distance from the nucleus? Or, are the bands just a fact of nature (sort of a "that's just the way it is as far as we can tell), which we have measured and accepted without and deeper understanding of cause?