Humphry Davy discovered that the chemical bonds between individual atoms in a molecule are electrical in nature.
We now know that chemical bonds are created by the sharing or transfer of electrically charged particles, electrons, between atoms. In 1800, the idea that chemistry somehow involved electricity was a radical discovery.
Davy’s discovery started the modern field of electrochemistry and redefined science’s view of chemical reactions and how chemicals bond together. Finally, Davy used this new concept to discover two new (and important) elements: sodium and potassium.
Humphry Davy was born in 1778 along the rugged coast of Cornwall, England. He received only minimal schooling and was mostly self-taught. As a young teenager, he was apprenticed to a surgeon and apothecary. But the early writings of famed French scientist Antoine Lavoisier sparked his interest in science.
In 1798 Davy was offered a chance by wealthy amateur chemist Thomas Beddoes to work in Bristol, England, at a new lab Beddoes built and funded. Davy was free to pursue chemistry-related science whims. He experimented with gases in 1799, thinking that the best way to test these colorless creations was to breathe them. He sniffed nitrous oxide (N2O) and passed out, remembering nothing but feeling happy and powerful.
After he reported its effect, the gas quickly became a popular party drug under the name “laughing gas.” Davy used nitrous oxide for a wisdom tooth extraction and felt no pain. Even though he reported this in an article, it was another 45 years before the medical profession finally used nitrous oxide as its first anesthetic.
Davy also experimented with carbon dioxide. He breathed it and almost died from carbon dioxide poisoning. A born showman, movie-star handsome, and always fashionably dressed, Davy delighted in staging grand demonstrations of each experiment and discovery for thrilled audiences of public admirers.
In 1799, Italian Alessandro Volta invented the battery and created the world’s first man-made electrical current. By 1803, Davy had talked Beddoes into building a giant “Voltaic Pile” (battery) with 110 double plates to provide more power.
Davy turned his full attention to experimenting with batteries. He tried different metals and even charcoal for the two electrodes in his battery and experimented with different liquids (water, acids, etc.) for the liquid (called an electrolyte) that filled the space around the battery’s plates.
In 1805 Davy noticed that a zinc electrode oxidized while the battery was connected. That was a chemical reaction taking place in the presence of an electrical current. Then he noticed other chemical reactions taking place on other electrodes. Davy realized that the battery (electric current) was causing chemical reactions to happen.
As he experimented with other electrodes, Davy began to realize the electrical nature of chemical reactions. He tried a wide variety of materials for the two electrodes and different liquids for the electrolyte.
In a grand demonstration in 1806, Davy passed a strong electric current through pure water and showed that he produced only two gasses, hydrogen and oxygen. Water molecules had been torn apart by an electric current. This demonstration showed that an electrical force could tear apart chemical bonds. To Davy this meant that the original chemical bonds had to be electrical in nature or an electric current couldn’t have ripped them apart.
Davy had discovered the basic nature of chemical bonding. Chemical bonds were somehow electrical. This discovery radically changed the way scientists viewed the formation of molecules and chemical bonds.
Davy continued experiments, passing electrical currents from electrode to electrode through almost every material he could find. In 1807 he tried the power of a new battery with 250 zinc and copper plates on caustic potash and isolated a new element that burst into brilliant flame as soon as it was formed on an electrode. He named it potassium. A month later he isolated sodium. Davy had used his grand discovery to discover two new elements.
A popular use of electrochemical bonding is in cookware. The process unites the anodized surface with the aluminum base, creating a nonporous surface that is 400 percent harder than aluminum.