The first chemistry book I ever read, a library book about atoms back in grade 9, was enjoyable. But in adolescence almost everything else I read, except for Dickens’ Great Expectations, appealed to me: encyclopedias, John Steinbeck novels, from books about airplanes Carlos Castaneda’s pseudo-anthropology, and Mad magazine. Similarly, when I took my first chemistry class the following year, I liked it. But again I found all courses, except for Canadian history, palatable. So what eventually made chemistry special?
1. It’s fun to use chemistry in everyday life. There’s acid in the snow, so neutralize it with lime in the spring. Reinforce the gluten network in pasta with a little lemon to ensure an al dente texture. Extract struvite, a fertilizer from urine with some epsom salts. Use simple calorimetry to estimate the efficiency of a microwave oven. Chloride from salt is unfortunately great at displacing iron(II) away from the coating of the initial steps of rusting. It exposes more elemental iron to oxygen and water, so it becomes even more important to wash and wax a car during North American winters.
2. Chemistry’s experiments are very sensitive to detail. As Primo Levi mentions in The Periodic Table,
One must distrust the almost-the-same, the practically identical, the approximate, the or-even, all surrogates, and all patchwork.
Although accidentally or deliberately changing a detail often leads to a mess, it also opens the pathway to discovery, and that’s what could make chemistry exciting.
3. Of course if those accidents occur on too large a scale, people and the environment can get hurt. What originally put me on a chemistry-career path before I turned to teaching was the fact that chemistry can be used to tackle many of the health and ecological problems that are created through a combination of crude science, unsustainable approaches and politics.
4. Being as fundamental as physics, chemistry gives us insight into other sciences: biology, geology, pharmacology, nutrition and so on. A biologist wondering about the origin of life cannot tackle the problem without considering chemiosmosis and chemical kinetics. How does a geologist explain the difference in color between rubies and emeralds without understanding the impurities’ effects on the ligand field of chromium(III) ion?
How does a pharmacologist rationalize the stimulating, pleasurable and anesthetic effects of cocaine without considering three separate chemical mechanisms? And eating black beans with rice makes sense because their essential amino acids (methionine and lysine, respectively) complement each other.
5. Questions and concepts about matter inspire experiments, which in turn lead to new ideas. This interplay leads to the evolution of a new language known as chemistry. Most people are indifferent or antagonistic towards chemistry because it is a foreign language to them. And languages are difficult to acquire past a certain age. Yet introduce it too early and chemistry becomes next to impossible to learn because of the abstractions and mathematics required. For those of us who caught on at just the right time in adolescence, we’re lucky to walk on Atkins’ bridge, linking our senses to that imagined world of atoms and molecules. As I write this, compounds from the parsley that I picked from the garden and handed to my wife linger on my fingers. The sensual experience is rich in itself, but it’s even more meaningful if I could relate the volatility to molecular size, which through the kinetic molecular theory affects the speed at which the smells reach my nasal receptors. What happens in the nose, a response elicited by intermolecular bonds with various receptors, is again chemistry.
6. While adding to one’s understanding of the universe, chemistry keeps one humble. Bohr’s model seemed to adequately explain the emission spectrum of hydrogen, but then it turned out that the lines were not as discrete as they seemed. There were sublevels for most of the electron’s energy levels, and you could never really pin down its location with 100% certainty. After decades of quantum mechanics, understanding periodicity(patterns of behaviour in the periodic table of elements) and investigating bonding in metal atoms, no one until recently could understand why gold atoms were so stingy and how they produced their startling color. Then it was realized that in select heavy elements, the acceleration of inner electrons to relativistic speeds affected atomic size and chemical properties. In cases where atoms are not stingy, when atoms engage in a gain and loss of electrons, in so-called oxidation-reduction reactions, things are not as simple as we imagined either. Thanks to the team of Nobelist Henry Taube we know that in certain inorganic exchanges (and, it turns out, in many biochemical ones too), there is a facilitating bridge for electrons between complex ions or molecules.
7. Understanding chemistry adds to my realization of how special life and human beings are. On the other hand, fragmented knowledge of the science can lead to disillusioned and nonsensical statements like this one from the 2001 movie Heartbreakers:
There’s no love. It’s the trick of the brain. It’s the combination of chemicals and hormones.
For starters, hormones are also chemical compounds, which do play some role in erotic love. But no one has any clue of all the mechanisms involved. We know remarkably little about the inner workings of the brain. And what both the public and specialised scientists also forget is that new interactions emerge at every level of the organisation of matter. Chemical bonding in all its forms respects the laws of physics. But from studying physics alone, one would never have imagined the three dimensional discrimination our enzymes have for chiral molecules (nonsuperimposable mirror images, like a left and right- handed gloves). You cannot make a banana in the lab even if you have the complete analytical breakdown of every compound in there. Some of the fruit’s properties emerge from its biology—its cellular structure and tissue behaviour, some of which is still active after it’s been picked. Similarly, as the chemistry and the assemblies of neurons in the brain constantly respond to genetics and to interactions with our physical and social environment, new properties emerge. For now and a long time to come, serious novelists, humanists and some everyday people will have a lot more to say about love than chemistry.