Welcome to The Sound of Science from WNIJ and NIU STEAM. It’s a weekly series explaining important STEM concepts. Today’s hosts are Jeremy Benson and Newt Likier.
Today's question comes from Bridget Moody, who asks, “How come on the periodic table gold is AU?”
Many of the element symbols seem pretty obvious, H for hydrogen, but then some of them like AU for gold don't seem to make much sense. The ancient Greeks were among the first to suspect that all matter was made from basic elements. But early scholars like Plato still considered these basic elements to be things like earth, wind, fire and water.
Around 350 BC, Aristotle defined an element as one of those simple bodies into which other bodies can be decomposed and which itself is not capable of being divided into others. But he still imagined those elements to be the four that Plato had taught him. Although he did add a fifth element, he called aether.
This view persisted for 2000 years until an English chemist named Robert Boyle revised Aristotle's definition. After that, scientists began cataloging chemical elements which met Boyle's criteria,
A Swedish chemist named JJ Berzelius has created the labeling system we use today. He chose a one or two letter symbol for each element based on its name at the time, because many of these substances had been known since ancient times. Some still used Latin names that would later be replaced with more common ones. For example, gold was originally called Aurum, giving us the symbol AU. The Latin root for lead is plumbum, giving it the symbol PB. This root can still be found in other modern words, such as plumbing and plumber, because in ancient times, water pipes were made from lead.
Russian scientist Dmitri Mendeleev then organized these elements into the periodic table that we all know and love today. While most are still called by the same names we used back then, others have changed since leaving their symbols as curious reminders of their history.
Thanks for the question, Bridget! Keep them coming.
This is The Sound of Science on WNIJ, where you learn something new every day.
