Have you every looked at the periodic table, and wondered how all of the elements came to be arranged in such an sensible and organized table? What about the missing elements that have yet to be discovered? Looking at the way the periodic table is built, some of us might wonder why scientists haven’t just taken some of the elements we can create, and added a proton to create the next element on the table. It seems so simple, but we must remember that the mystery of science wouldn’t be exciting if it was that easy!
What makes an element stable? Is it size? But some elements that are smaller are more stable than the heavier elements that follow it. There’s more to it…and nuclear chemists call that the “Island of Stability“
In nuclear physics, the island of stability is the prediction that a set of heavy isotopes with a near magic number of protons and neutrons will temporarily reverse the trend of decreasing stability in elements heavier than uranium.
Initially, during the creation of the solar system the intense heat and pressure resulted in the creation of the first ninety two elements, which are the building blocks to all matter. Uranium (atomic number ninety two) is the last of the naturally occurring elements. After that, all the known elements have been created by scientists, a project that was pioneered by Glenn Seaborg, the eponym of seaborgium (atomic number 106) and Nobel Peace Prize recipient. Seaborg was able to artificially add an extra proton to proceeding elements to continue the periodic table, creating Plutonium, Americium, Curium, Berkelium, Californium, Mendelevium and Nobelium. At Nobelium he hit a major roadblock, which would later help to explain the inner workings of the periodic table.
In an atom, the protons found in the nucleus are constantly repelling each other since they are of the same charge. The only thing keeping them together is a nuclear force called The Strong Force. The Strong Force acts like a bungie cord that connects the protons, so when they pull apart, the strong force pulls them back together. But like a bungie cord, if they pull to far out the force will “snap” and not pull them back. Neutrons act like a mediator between the protons too, keeping them together with its own type of bungie cord.
Eventually, however, the force of the protons will overcome the strong force, and the element can’t physically exist with that particular amount of protons. The elements that form closer and closer to this braking point become increasingly unstable, and exist for an increasingly smaller amount of time. This is the roadblock that Seaborg faced, as he kept adding more protons to an atom they eventually started falling apart.
Seaborg created his own analogy for this problem, he thought of the elements as an island surrounded by a sea of instability, and the island ended with element 102 – Nobelium (which at the time was the last discovered element on the table)
In 1950, scientists came across a new discovery that would break through the barrier Seaborg faced. They found that the protons and neutrons in the nucleus were organized in a stringent order, similar to the electron orbitals in Bohr-Rutherford diagrams. These rings create a greater degree of stability then if the nucleus where a random disorganized mess, giving scientists hope. Similar to electron orbitals, they found that the stability of these rings depend on the number of protons and neutrons in the rings, having the right number of protons results in a “magic” configuration and having the ideal number of protons and neutrons results in a “doubly magic” configuration which is maximum stability and the strongest nuclear configuration. So in theory although element 114 is incredibly large it is also very very stable since it is doubly magic with 114 protons and 184 neutrons.
Scientists could then conclude that instead of adding one proton at a time, he should be adding twenty or forty at a time in order to jump over the sea of instability and create super heavy elements. In order to add these protons and neutrons together scientists use particle accelerators like the Large Hadron Collider at CERN’s accelerator complex to smash the elements together, like bowling balls and bins. Sometimes it can take 10 x 10^19 or 10 billion billion attempts to get the two elements to intersect.
In 2009 scientists at Energy’s Lawrence Berkeley National Laboratory managed to create element number 114 for the first time, confirming the existence of these long theorized super heavy elements.
Villanova College Chemistry Blog 