The Seventh Row

Well, "complete" is generous. The seventh row is complete. Rows eight through infinity presumably have their own plans, but for now, the chart of matter — the thing hanging in every high school chemistry classroom, stained with dry-erase marker and existential dread — has no more blanks.

IUPAC, the international body that gets to name things made of quarks and ambition, officially christened four new elements in 2016: nihonium (Nh, 113), moscovium (Mc, 115), tennessine (Ts, 117), and oganesson (Og, 118). The seventh row snapped shut. Scientists opened champagne. The universe did not notice.

Here's the part that breaks your brain: these elements don't really exist. Not in any sense the periodic table's original architects — Mendeleev staring at element cards in 1869 — would have recognized. They're synthesized in particle accelerators by smashing lighter atoms together at enormous speeds and waiting to see if something new falls out. The odds of success are roughly "win the lottery while being struck by lightning." Most attempts produce nothing. Occasionally, for a few milliseconds, an atom exists.

Oganesson — element 118, the last slot — has a half-life of about 0.89 milliseconds. Scientists have confirmed roughly five atoms of it. Ever. Total. The element exists as a footnote that briefly had a heartbeat.

And yet: it gets a name. A permanent place on the table. Because the table isn't about stability or abundance or usefulness. It's about what's possible — every configuration of protons that physics permits, including the ones that immediately decay into something else before you've finished pronouncing their names.

The weirder fact is what oganesson should be, versus what it probably is. Column 18 on the periodic table is the noble gases — helium, neon, argon, the aloof ones that don't bond with anything, chemically inert by their structure. Oganesson sits at the bottom of that column and should, by all rights, be a noble gas too.

It almost certainly isn't.

Relativistic effects — what happens when electrons are moving so fast around a very heavy nucleus that Einstein's special relativity kicks in and changes their behavior — likely make oganesson reactive. Maybe a solid at room temperature. A noble gas that bonds with things. An inert element that isn't inert. The category that describes it is immediately violated by it.

This is the periodic table's cosmic joke: we finally filled in the chart, and the last element breaks the chart.

Nihonium (element 113) went to a Japanese research team — the first element discovered in Asia, named after Nihon, the Japanese word for Japan. Moscovium went to a Russian-American collaboration, tennessine to Tennessee's Oak Ridge National Laboratory and Vanderbilt University. Oganesson was named for Yuri Oganessian, a living physicist — only the second time in history a confirmed element has been named for a living person.

So: the universe contains 118 flavors of atom. We've found them all. The last four exist for durations measured in thousandths of seconds. One of them probably doesn't behave like its category suggests. Its namesake is still alive and presumably finds this amusing.

The periodic table is a map of all possible matter. It's also a reminder that "possible" includes things that briefly flicker into existence and then dissolve, that categories are suggestions physics sometimes ignores, and that the chart you memorized in school has an edge — beyond which we don't know what waits.

Row eight starts at element 119. Nobody's made it yet.

The void is patient.