Easy as un-bi-tri? Naming new elements

Recently, the International Union of Pure and Applied Chemistry (IUPAC) added four new elements to the periodic table. They are temporarily known as ununtrium, ununpentium, ununseptium, and ununoctium.

That’s a daunting lot of u’s, but the nomenclature behind them is actually pretty, um, elementary – which is about the only thing that seems simple when it comes to the business of chemistry, if you ask me.

Actually, even the naming can get pretty complicated, if you dig deep enough, but here’s a basic breakdown, with a little etymology mixed in.

The whys of all the u‘s 

Before receiving permanent names, new elements take on provisional ones, called “systematic names,” according to the IUPAC’s official guidelines.

These systematic names are based on the elements’ atomic numbers and derived from Latin and Greek roots for numerals.

Let’s take ununtrium. This is element 113, as the element has 113 protons. Ununtrium literally and sequentially links Latin roots for digits 1, 1, and 3. (As opposed to the Latin for one hundred and thirteen, which I believe is centum et tredecim, but don’t necessarily count on that).

And just to be clear, the Latin root for one is un-, from ūnus. For three we have tri-, formed on trēs.

Then, we tack on the suffix –ium, used to name metallic elements. Indeed, these elements, completing the periodic table’s seventh row, are some truly superheavy, if incredibly short-lived, metals synthesized in the laboratory.

Now, the Latin words for many elements – like gold, or aurum, and iron, ferrum – end in –um. The Oxford English Dictionary observes that Cornish scientist Humphry Davy, who discovered a number of metals such as potassium and sodium, helped propel the -ium suffix back in 1807. Based on the compounds Davy was electrolyzing, potassium is formed on potash and sodium, soda. And so from these –ium largely prevailed ever since.

Ununpentium follows the pattern but uses the Greek root for five, pent-, apparently to avoid confusion between Latin’s quad– (for digit 4) and quint– (for digit 5).  Ununseptium and ununoctium continue with the Latin roots for seven (sept-) and eight (oct-).

And the temporary chemical symbols of the new elements– Uut, Uup, Uus, and Uu0 – simply abbreviate the initial letter of their component numerical roots. Easy as un-, bi-, tri-, right?

All this once made element 111, now officially roentgenium, quite the u-ful: unununium, with chemical symbol Uuu.

Name game, round 2

Next, the new elements’ discoverers will submit recommendations for permanent names to the IUPAC, which reviews them for suitability, especially for use across languages. According to the IUPAC’s guidelines, the new names must be based on a mythological concept or character, a mineral or similar substance, a place or geographical region, a property the element displays, or a scientist.

If recent discoveries are any measure, the new names will likely honor the laboratories or nationalities of the scientists. So, the Japanese scientists who synthesized ununtrium may submit japonium for the official name.

You can read the IUPAC’s official recommendations for naming new elements here. For more on the history of the IUPAC’s recommendations, I recommend this piece by Quartz. I also enjoyed the BBC’s take on how elements get their names. And for some more general information on the elements, head over to NPR.

Next post, we’ll look into the origin of the very word element, which turns out to be far from basic.

m ∫ r ∫