An integral part of every science classroom is the Periodic Table of the Elements, and for many it is the first introduction to the great mysteries of nature.
Now physicists from the University of Kyoto have presented a new table that offers a different perspective on the building blocks of the universe. While the traditional table is based on the behavior of the electrons in an atom, this new table is based on the protons in the nucleus.
“The Periodic Table of the Elements is one of the most important achievements in science, and in its well-known form it is based on the shell structure of electron orbitals in atoms,” explains Yoshiteru Maeno, one of the co-developers of the new system.
“But atoms are made up of two types of charged particles that identify each element: electrons orbiting the nucleus and protons in the nucleus itself.
The team’s new ‘Nucletouch’ table – also available as a 3D model – was recently published in the magazine Foundations of Chemistry announced.
More than 150 years have passed since Dmitry Mendeleev discovered the periodic law that prompted him to propose the classic periodic table. He even had the foresight to make room for elements that were unknown at the time.
“Basically, it depends on the electrons in every atom. Atoms are considered stable when the electrons completely fill their ‘shell’ of orbits around the nucleus,” continues Maeno.
“So-called ‘noble gases’, inert elements such as helium, neon and argon, rarely react with other elements. Their most stable electron numbers are 2, 10, 18, 36 and so on.”
Maeno describes these as atomic “magic numbers”, and it is important that the same principle can be applied to protons. To imagine that protons in a nucleus exist in “orbits” may seem like an extension, but the discovery of the concept was awarded the Nobel Prize in Physics in 1963.
Protons have different stable magic numbers: 2, 8, 20, 28 and so on. These include well-known elements such as helium, oxygen and calcium. The Nucletouch table places these “magic cores” at its center and thus offers a new perspective on the elements.
“Similar to electrons, when their nuclear orbits are filled with protons, they form stable nuclei, analogous to the noble gas elements,” says collaborator Kouichi Hagino.
“In our nuclear periodic table, we also see that nuclei tend to be spherical near the magic numbers, but they deform when you move away from them.
The team has created the table to show alternative ways of illustrating the laws of nature, and hopes that both enthusiasts and academics will find something to enjoy and learn from this fresh, new look at an old friend.