We traditionally meet this requirement by saying that different bonds are distinctly different from each other because they are in different places. But, by the premise of WikiMechanics, we cannot resort to satisfying Pauli's exclusion principle by resorting to a spatial explanation for their differences. Rather, we differentiate them by association with different chemical seeds. We cannot use any thermodyamic seed to make the distinction between electrons because they're already constrained by earlier hypotheses.

WikiMechanics portrays*molecules*as compound atoms that are held together by chemical bonds. The bonds that we consider here are defined from pairs of electrons, they are

**covalent bonds**. We intend to treat these bonds as countable entities, as for example in Lewis dot diagrams or VSEPR theory. So we need to follow some rules of logic and mathematics. Specifically, by Pauli's exclusion principle we cannot have two identical electrons in the same set. So we need to distinguish electrons from each other. And, in molecules with more than one bond, we need to distinguish bonds from each other too.

Don't forget about other sensations. Click here for more … |

We need at least three logically distinct bonds to extend Cartesian coordinates to outlying atoms in the oxygen-centered description.

The three bonds $\mathbb{B}\small{\sf{(line) }}$, $\mathbb{B}\small{\sf{(hash) }}$ and $\mathbb{B}\small{\sf{(wedge) }}$ are defined from three distinct classes of taste sensation which can vary independently from each other. We will use them to define a three-dimensional Cartesian coordinate system for describing molecules.

x and y axes are defined in principle, but after spinning the atoms and invoking the hypothesis of spatial isotropy, they have been shorn of any connection to visual sensations. So to describe spaces for particles that are atoms and molecules, we now will construct an extended three-dimensional based on measurements of length. For which we must explicitly consider what atoms we're talking about.

A Cartesian coordinate system centered on the oxygen atom (the red ball) in a molecule of water. The blue balls represent hydrogen atoms. |

But after properly defining extended three-dimensional space, we can assume that the two bonds are distinct because they are in different places. (This semantically liberates the bond-symbols defined above in much the same way as the hypothesis of spatial isotropy frees the use of color terms.) Then we drop the wedge-shaped symbol to represent water with the simpler diagram

This simplification is important for complicated chemical structures.