Junk Science

The Periodic Table Has New Elements, But You Can’t See Them

There are four new elements in the periodic table. And most of them can only exist for a handful of milliseconds

Junk Science
(Illustration: Vocativ)
Jan 05, 2016 at 1:54 PM ET

Chemists are welcoming four new elements to the periodic table—but they’re not here to stay.

The elements have long existed in theory as placeholders on the bottom row or “seventh period” of the periodic table but, with the IUPAC’s stamp of approval, the discoveries of elements 113 (Uut), 115 (Uup), 117 (Uus) and 118 (Uuo) are now considered official (although, thankfully, their drab names are only temporary), according to the International Union of Pure and Applied Chemistry.

These numbers refer to each new elements’ atomic number, which indicates how many protons an atom of each element has in its nucleus. Scientists synthesized these rare elements by bombarding thin sheets of more stable elements with charged particles traveling just shy of the speed of light. In the case of Uut, Japanese researchers bombarded a layer of Bismuth (which has an atomic number of 83) with charged Zinc (atomic number 30) particles until the atoms fused, forming element 113.

But you still can’t see them.

In fact, in most cases you can’t even keep these new elements in existence for more than a couple of milliseconds before they rapidly decay. In general, the larger an atom’s atomic number (and, thus, the more protons it possesses), the less stable it is. That’s because all those positively charged protons in the nucleus begin to repel one another, causing the atom to decay.

So when IUPAC recognizes that the new elements have been discovered, that doesn’t quite mean they are ready for use in medicine or industry—or, indeed, that we’ll ever be able to do anything with them at all. “Discovered” is a relatively low bar in chemistry (and indeed, many elements are actually discovered decades before they are officially recognized—element 118, for instance, was first reported in 1999 but only today, after sixteen years of follow-up experiments, was it finally recognized by the IUPAC).

In fact, at least 18 elements of the periodic table are so radioactive and unstable that their half-lives (the amount of time it takes for half the substance to decay) are under than 24 hours. Bohrium, for instance, has a half-life of approximately one minute—so if you manage to get your hands on 10 pounds of Bohrium, you’ll have only 5 pounds one minute later, and only 2.5 pounds one minute after that. Within an hour, you’ll barely have any Bohrium left.

This gets annoying fast. One of the newly added elements, Ununtrium, has a half-life of only 20 seconds. Ununoctium, another new element, takes less than one millisecond to decay by half. It hardly exists at all.

On one hand, this is an incredible story about the resilience of the scientific enterprise. Chemistry has advanced in leaps and bounds, and now that we can smash atoms and electrons together in successively larger and more impressive machines, it is possible to isolate elements that exist for a fraction of a second. And just because we can’t think of any practical applications for such short-lived elements right now doesn’t mean that we won’t use for them down the line. One of the key assumptions of quantum theory is that, once we’ve gotten these unstable elements under our belt, we’ll find an entirely new class of extremely stable elements further down the periodic table—a so-called “island of stability”, with myriad industrial and medical applications.

And lest we forget, these final four pieces of the puzzle complete the last row of the periodic table, finishing the work that Dmitri Mendeleev who started the table almost 150 years ago. The current periodic table came together throughout the 19th century, with blank spaces marking the locations of elements that had been hypothesized, but never observed. It wasn’t until the 1940s that chemists began to painstakingly work their way through the most unstable, radioactive elements. And it wasn’t until 2016 that four of the most elusive elements—the final blank spaces in the seventh period—gained official approval from IUPAC.

On the other hand, it’s a bit of let down. Sure, the final row of the periodic table is now present and accounted for, but only for a couple of seconds and under rigorous laboratory conditions. But personal feelings aside, it’s still a big day for chemistry, one for the science history books. Welcome to the elemental family, Uut, Uup, Uus and Uuo—even if you’re only around periodically.