Elegant and seductive, the periodic table may be the bane of chemistry students everywhere. Impeccably organized, it lists all the known elements in order of increasing atomic number. At the same time, it fiendishly — as any high school chemistry student will attest — arranges them in rows and columns that emphasize common structures and behaviors. Electronegativity, anyone?
Elements have been known to humans since ancient times. Copper, which occurs in pure form, was mined and crafted in the Middle East around 9000 BC. It took another 2000 years before lead was discovered, then gold, silver and iron at about 1000-year intervals. The discovery and use of carbon, tin, sulfur, mercury, zinc, bismuth, arsenic and antimony followed, bringing us to about AD 800. But early miners, metallurgists and alchemists had no concept of what an element was; they only knew that these materials seemingly could not to be broken down into smaller or simpler substances.
A new element did not appear for another 850 years. With the discovery of phosphorus, in 1669, by Hennig Brand, scientists came to better understand the underlying nature of what an element was. (Although it was not until 1913 that elements were defined by the number of protons in their nuclei.) Brand, a German alchemist, was working secretly to discover the philosopher’s stone, that legendary substance that could turn lead into gold. In one of his experiments he allowed urine to evaporate, then heated the residue. Presto, phosphorus!
Suddenly, new elements began virtually popping out of the woodwork. By 1869, 64 elements had been discovered. Several scientists by then had made attempts to classify or categorize the elements, but it was Russian chemist Dmitri Mendeleev, in 1869, who first proposed the schema that evolved into today’s periodic table.
As of 2019 — 150 years later — we have 118 known elements. Of those, 92 (or 94, depending on the source) occur naturally on earth, though some, like plutonium, exist only in minuscule quantities. The remaining elements have been synthesized in laboratories and may have existed physically only for fractions of a second!
In 2017, The United Nations General Assembly proclaimed that 2019 would be the International Year of the Periodic Table of Chemical Elements, or IYPT 2019. Celebrations have taken place all around the world, including a book of haiku about the elements. You can learn more about the ingenious ways that the Periodic Table has been celebrated at the official IYPT website. And you may decide, after all, that it’s pretty cool. And if chemistry sometimes baffles you, Morris Tutoring is ready to help.