Orbitals Human Inventions

For example, after all of the talk about orbitals in the last several chapters, you probably have the distinct impression that orbitals actually exist. The truth is, they do not—at least not in the physical sense. Orbitals are mathematical functions—solutions to a modified Schrodinger equation (the changes made to allow separation into independent electron equations). 

Thus orbitals are mathematical tools we use to describe atoms and molecules. However, they have no physical reality in the sense that if you could look at a water molecule, you would probably not see anything like the pictures we have shown in this book. These pictures merely help us visualize the theoretical information we have accumulated for water. 

We should also make clear that much more sophisticated treatments of atoms and molecules than we have considered here do exist and are carried out quite routinely by chemists who specialize in this area. These quantum mechanical calculations involve many fewer approximations than are made to obtain the models we have discussed here. However, although these treatments produce accurate mathematical descriptions of atomic and molecular properties, they are usually very difficult to interpret physically. 

There is another point that should be made in connection with the theories of atoms and molecules. Even the experts in the field disagree (sometimes violently) about what the mathematical descriptions of atoms and molecules 

Thus orbitals are mathematical tools we use to describe atoms and molecules. However, they have no physical reality in the sense that if you could 

Martin, Localized and Spectroscopic Orbitals Squirrel Ears on Water, /. Chem. Ed. 65 (1988) 688. 

Scerri, Have Orbitals Really Been Observed J. Chem. Ed. 77 (2000) 1492. Bacskay, Reimers, and Nordholm,/. Chem. Ed. 74 (1997), 1494. 

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In fact, all societies have invented constellations.4 The ones with which we are now familiar were developed so long ago that some of their origin is a mystery. Astro-historians believe they go back to the Mesopotamia of 2000 b.c. The earliest constellation maps were adopted by the ancient Greeks and then by the Romans who gave them Latin names that we use today. In a sense, the constellations are a record and reflection of human civilizations and their thinking (figure 9.1). The most famous constellations are in the zodiac, a set of 12 constellations that lie along the ecliptic, the plane of the Earth s orbit and of the Sun s apparent annual path. Here we see Leo the Lion, Taurus... 

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