Chemical Bond Quotes (6 quotes)
For Christmas, 1939, a girl friend gave me a book token which I used to buy Linus Pauling's recently published Nature of the Chemical Bond. His book transformed the chemical flatland of my earlier textbooks into a world of three-dimensional structures.
It is structure that we look for whenever we try to understand anything. All science is built upon this search; we investigate how the cell is built of reticular material, cytoplasm, chromosomes; how crystals aggregate; how atoms are fastened together; how electrons constitute a chemical bond between atoms. We like to understand, and to explain, observed facts in terms of structure. A chemist who understands why a diamond has certain properties, or why nylon or hemoglobin have other properties, because of the different ways their atoms are arranged, may ask questions that a geologist would not think of formulating, unless he had been similarly trained in this way of thinking about the world.
One is almost tempted to say... at last I can almost see a bond. But that will never be, for a bond does not really exist at all: it is a most convenient fiction which, as we have seen, is convenient both to experimental and theoretical chemists.
THE fundamental questions in chemistry,â€”those questions the answers to which would convert chemistry into a branch of exact science, and enable us to predict with absolute certainty the result of every reactionâ€”are (1) What is the nature of the forces which retain the several molecules or atoms of a compound together? and (2) How may their direction and amount be determined? We may safely say that, in the present state of the science, these questions cannot be answered; and it is extremely doubtful whether any future advances will render their solution possible.
When carbon (C), Oxygen (o) and hydrogen (H) atoms bond in a certain way to form sugar, the resulting compound has a sweet taste. The sweetness resides neither in the C, nor in the O, nor in the H; it resides in the pattern that emerges from their interaction. It is an emergent property. Moreover, strictly speaking, is not a property of the chemical bonds. It is a sensory experience that arises when the sugar molecules interact with the chemistry of our taste buds, which in turns causes a set of neurons to fire in a certain way. The experience of sweetness emerges from that neural activity.
[The chemical bond] First, it is related to the disposition of two electrons (remember, no one has ever seen an electron!): next, these electrons have their spins pointing in opposite directions (remember, no one can ever measure the spin of a particular electron!): then, the spatial distribution of these electrons is described analytically with some degree of precision (remember, there is no way of distinguishing experimentally the density distribution of one electron from another!): concepts like hybridization, covalent and ionic structures, resonance, all appear, not one of which corresponds to anything that is directly measurable. These concepts make a chemical bond seem so real, so life-like, that I can almost see it. Then I wake with a shock to the realization that a chemical bond does not exist; it is a figment of the imagination that we have invented, and no more real than the square root of - 1. I will not say that the known is explained in terms of the unknown, for that is to misconstrue the sense of intellectual adventure. There is no explanation: there is form: there is structure: there is symmetry: there is growth: and there is therefore change and life.