You may have heard that the Periodic Table is a little fuller this year than last. That’s because the IUPAC has officially added 4 new elements to the periodic table. This is cool, but what does it mean? And why are we just now finding out about these elements?
The periodic table was invented and first published in 1869 by Dmitry Mendeleyev. The rows group the elements by their atomic weight. The columns denote how many electrons exist in the outermost layer of the atom, or the ‘Valence Shell’. When Mendeleyev laid this table out he noticed a few empty spots. He posited that these elements do exist and we just hadn’t discovered them yet. This turned out to be true as in the following years we discovered scandium, gallium, and germanium and surprise, they fit right into the empty spots on mendeleyevs table.
The Periodic Law was laid out after 1911 when an english chemist named Henry Mosely came up with a better way to quantify the scale of the elements, which turned out to be finding the number of protons in the nucleus which is the modern method used to lay out the periodic table. Once again this left some holes in the table which, using Moseley’s method of measuring x-rays given off by an element when bombarded with electrons, were later filled by newly discovered elements.
The most recent 4 elements added were actually discovered in 2002, 2003, and 2010. After a few more years of study and verification by other labs we now have a full 7th row in our periodic table. Elements 113, 115, 117, and 118, welcome to the party.