Modern-day alchemists

Taking pride of place in almost every chemistry classroom in the world is the periodic table. And this year, Mendeleev’s invention became more beautiful than it has ever been.

When Mendeleev published the table in 1869, it held 63 elements. But perhaps the most brilliant thing about it was that it also contained gaps. The filling of those gaps with newly discovered elements was the reason it gained acceptance. 150 years later it remains the most used theoretical tool in the chemist’s arsenal. But one set of gaps is particularly interesting: the infinitely long list of elements awaiting discovery at its end. This year saw the recognition of the latest four elements, with atomic numbers 113, 115, 117 and 118. The periodic table now contains no internal gaps. It’s perfect in shape. But will physicists destroy this perfection with the discovery of elements 119, 120, 121?

My colleague Philip Robinson and I travelled to California to meet some of the scientists that make and study these superheavy elements. They explained to us how the elements are made and identified, and about the prospect of expanding the periodic table further.