Final answer:
The question involves the visualization of atomic structures, changes in atomic radius during ion formation, electron probability densities, and trends of atomic radius within the periodic table. It requires understanding atomic and electronic structures in chemistry, particularly for elements like aluminum and sulfur, as well as the hydrogen atom's orbitals.
Step-by-step explanation:
The question provided touches on several concepts related to chemistry, particularly atomic structure, celestial spheres as an analogy, and electron probability densities. First, the description of the celestial sphere is metaphorical and helps visualize the system of coordinates in the sky, but it is not directly related to chemistry. The provided values a, b, and c seem to refer to locations on a sphere or concepts in electron distribution, but without a specific context or figure, it's challenging to provide an accurate location for these values.
The mention of green spheres representing the size of atoms indicates a discussion of atomic radius, particularly how it changes during ionic formation, such as aluminum becoming smaller when it loses electrons to form a cation, while sulfur becomes larger when it gains electrons to form an anion. The electron probability density refers to the likelihood of finding an electron in a particular location around the nucleus and is essential for understanding atomic structure, particularly in hydrogen's 1s, 2s, and 3s orbitals, where spherical nodes mark regions of zero probability. Lastly, the graph showing a trend in atomic radius across the periodic table helps visualize how atomic radius varies among elements, often decreasing across a period and increasing down a group, with noticeable changes at alkali metals and noble gases.