Fatima Garcia

SLAM Talk Title: "The Great Periodic Table Debate"

How did you originally get interested in science?

As a kid, I was always taking things apart. I wanted to know how and why they worked. I wasn’t always successful at putting them back together, but I was curious about the pieces that you would need and how they all fit together to make things work. It’s funny to think that my naive curiosity turned into the study of what atoms are composed of and how nuclei work.

What is your favorite place at the Lab?

The tables on the roof of B88. Lunch out there is fantastic with an amazing view of the bay and great company.

Most memorable moment at the Lab?

Walking into the 88-inch cyclotron control room was an experience. It was like stepping into a time-machine stuck in two different eras: ancient buttons and dials, some of which likely predate me by three decades, sitting next to state-of-the-art components and next-generation control software, all working together to power the machine that makes my research possible. It was incredible.

What are your hobbies or interests outside the Lab?

Baking, knitting, pottery, playing video games, reading, playing Dungeons and Dragons.

Fatima's Script - "The Great Periodic Table Debate"

You know the shape. You might remember from grade school that the columns and rows are meaningful, and maybe you’ll recall that there were some empty spaces towards the end that needed to be filled. The periodic table of elements has been hanging in classrooms and chemistry labs all over the world for decades. So what would you do if I were to tell you that the table’s classification system might not be totally right?

The table arranges the elements based on their proton numbers, that’s how we define them to be elements. They are also arranged based on their electron configurations and it is the electrons that give elements their chemical properties, with the rows, or groups of the table containing chemically similar elements. For 150 years the table has allowed us to predict what new elements were going to do based on their placements, before they were discovered. Until, that is, we started discovering the super heavy elements. These are elements above number 102, and they’re starting to behave in really strange ways. Oganesson for example, element 118 and one of the last ones to be named in 2016, should be the last noble gas on the table, but word is that it’s behaving more like the volatile elements of in the nitrogen group, whereas Copernicium, element 112, named after the father of the heliocentric model of the solar system, is behaving more like the noble gases. If we maintain the numerical ordering, the chemical properties don’t follow and if we maintain the chemical properties the numerical order no longer makes sense. And this is just one of the conundrums facing the table, with an international team of scientists trying to determine if we should just adopt a convention, sparking a debate about one of the most celebrated members of the scientific community. Maybe the shape needs to change. The community has asked for further experiments and information to try and figure out what to do.

However, experiments with the superheavies are difficult to do. The first hurdle is that they’re pretty difficult to make, typically made at the rate of one atom a week or one atom a month. After making them, you then have to watch them react, but since they’re highly radioactive, you have to take your measurements fast enough before your element decays away. This is exactly what we do in the Heavy Elements group at Berkeley lab. Doing modern day alchemy, we make a superheavy element by shooting a beam of particles at a stationary target, and after making our ion we trap it with a series of electric fields, and into the trap, we inject a series of volatile gases to watch the chemical reactions in atom-at-a-time chemistry. By using many gases, we can gain information about the chemical properties and thereby the electron configurations of these exotic elements.

At the rate of one atom a week or one atom a month, it will take a while, but our results will serve to expand the knowledge of the chemistry of the superheavies, and hopefully one day we can settle the great periodic table debate. Maybe in a decade or two the periodic table of elements won’t look like a table anymore.