The periodic table is instantly recognizable. This well-known chart is found in chemistry textbooks and on classroom walls. It lays out all the known elements and has been around in various forms for more than 150 years. But the version of that chart that Russian scientist Dmitri Mendeleev constructed in 1869 isn’t the same chart we see today.
Back then, his chart contained only 63 elements. They were all that were known. Mendeleev left gaps in his table where predicted, but not yet known, elements should fit. And once scientists found all the naturally occurring ones, they started bombarding two elements together to create new elements. Today, the table has 118 known elements.
Want to know more? We’ve got some stories to get you started:
Chemistry’s ever-useful periodic table celebrates a big birthday: Now 150 years old, this ‘table’ can take many forms, from block charts to spiral trees — and for good reason (11/21/2019) Readability: 8.2
The newest elements finally have names: Nihonium? Tennessine? These aren’t body parts or medicines. They’re among the names just given to the four newest superheavy elements. (6/8/2016) Readability: 8.5
Astronomers finally find the cosmic source of gold and silver: Gravitational waves point to answers for some longstanding mysteries of the universe (10/16/2017) Readability 8.1
Go on a periodic scavenger hunt while you’re stuck at home. How many elements can you find without leaving your house?