The Periodic Table’s Four New Elements

8 Jan 2016 - 08:30
The Periodic Tables 4 New Elements

If you take even the slightest interest in chemistry news, you’ll probably already have heard about the official confirmation of the discovery of four new elements, which even achieved widespread coverage in mainstream news outlets. IUPAC (the International Union of Pure and Applied Chemistry) sneaked out the news just before New Year’s Eve without much prior warning, and without a great deal of fanfare, though some had already predicted that an announcement of the sort was imminent. So what do we actually know about these new elements?

It might make sense to start by discussing how they were created. These are synthetic elements – that is, they do not occur naturally. Nobody’s going to go out and stumble across a sample of any of these four ‘out in the wild’, because they can only be created in laboratories. When put in simple terms, the process via which this is accomplished sounds rather lacking in finesse: essentially atoms of two different elements are smashed together, in the hope that they’ll combine into a single, larger element.

This is exactly how all four of the newly confirmed elements were created, though the specifics of the method make clear how arduous a process this is. It’s not quite enough for the atoms to simply bash into each other; they must instead do so at an incredibly high speed. In order to accomplish this, a particle accelerator is used, which accelerates ions to a speed of millions of miles per hour. This beam of ions is then targeted at atoms of the other element which it is hoped they will be combined with.

The issue with the process is that very few impacts actually have the correct speed and orientation to lead to fusion of the two elements and create a new element. In fact, ‘very few’ is probably something of an understatement – perhaps only one impact in every few billion actually succeeds in creating the desired new element. Most of the collisions either result in deflection of the two atoms, or the utter annihilation of both of them. Because of this, the experiments through which scientists seek to create and identify these elements often run for months on end.

Even when these superheavy elements are successfully produced, there’s another issue: their instability. Some elements that occur naturally are themselves unstable, and undergo radioactive decay to other, smaller element fragments. The superheavy elements take this to a whole new level. They, too, undergo radioactive decay fractions of a second after being produced, and this radioactive decay can be detected. More often than not, the evidence for the creation of a new element is the tell-tale trail of elements it decays into shortly after its creation.

As they only exist for the merest fraction of a second, it’s hard to know much about these new elements. We can’t even say for certain whether they’re solids, liquids, or gases at room temperature, since we can’t measure their melting or boiling points during the very short time frame for which they exist. That said, it’s a pretty good bet that they’re likely to all be solids. We can’t infer much about their properties from the groups of the periodic table they’re in either. This is because they’re so heavy, and their huge mass and large number of electrons can lead to some weird, trend-bucking properties.

Actually, we don’t even know their names yet. Ununtrium, ununpentium, ununseptium and ununoctium are merely formulaic latin place-holders, added to the periodic table to stand in until proof of the elements’ existence was produced. Now that this proof has been confirmed, the research teams that have been anointed as the official discoverers of the elements will be invited by IUPAC to suggest names and symbols, and we won’t have names for these new elements until their suggestions are vetted. We can, however, speculate.

Element naming actually follows a strict set of rules as of 2002, in the wake of squabbles between the USA and Russia over the naming of elements 104-109. Philip Ball elucidates them in a Chemistry World article here, the take-home points of which are that “elements may be named after mythical characters or concepts, minerals, geographical places, element properties… or scientists.” The rules also stipulate that element names should end in ‘-ium’, with the exception of groups 17 and 18, which should end in ‘-ine’ and ‘-on’ respectively to maintain naming consistency down the group. The large number of people currently petitioning for element 118 to be called ‘Lemmium’ after the recently deceased Motörhead frontman, Ian ‘Lemmy’ Kilmister, might be a tad disappointed to learn that the name ‘Lemmon’ would actually be the outcome of their petition being successful.

There’s little hint at present as to the names that will be suggested for elements 115, 117, and 118. 113, though, is a little less shrouded in mystery. Being, as it is, the first elemental discovery to be credited to Asia, there’s speculation that it could be named after the country the institute that discovered it is based in: Japan. Japanium could be a possibility, and could end decades of frustration for those who can’t spell their letter-j-containing names with element symbols. If the country-name route is taken, though, Nihonium, after the Japanese name for Japan, is more likely. Alternatively, it could be named after the RIKEN institute at which it was discovered. Or they could throw everyone a curveball, and name it after something (or someone) else entirely!

The road to naming the elements is likely to be slightly shorter than the time taken to confirm their discovery. Work on discovering element 113 began all the way back in 2002, so it’s been a long wait for the scientists involved to see the fruits of their labours. By way of reference, the last two elements to receive permanent names were flerovium (element 114) and livermorium (element 116); these both had their discoveries confirmed in 2011, and their names subsequently confirmed around a year later in 2012. So it seems likely that this time next year, we’ll finally be able to induct these four new elements into the periodic table properly, and the seventh row of the periodic table will then be complete.

You might well be left wondering what the motivation is for the scientists who work on discovering these elements. What’s the incentive to create elemental entities that exist for milliseconds or less before winking out of existence by transforming into other elements that are already known? Obviously these elements don’t have any useful applications, but the scientists running the experiments are holding out hope for the possibility of an ‘island of stability’.

The ‘island of stability’ is a theorised group of superheavy elements, beyond those that scientists have managed to synthesise to date. The reason they believe this is actually quite complicated, and has to do with the way in which the protons and neutrons in the nuclei of atoms are arranged. Based on this, they suspect that even heavier elements than those currently known could actually be more stable, and maybe exist for days or even weeks.

Work is still ongoing to reach this island. The periodic table may now appear complete, with the addition of the final four pieces of its seventh row, but now the race is on to produce element 119, and add a new row to the table. At present, the heavier the element, the harder its creation becomes, and several labs have tried to produce element 119 without success. As such, the four elements added to the periodic table this year may be the last added for a number of years.