Scientists in Japan have created two new forms of oxygen that exhibit unusual properties compared to commonly understood atomic structure theories.
Oxygen-28, one of the two newly created isotopes, is the heaviest oxygen isotope ever known. It also behaves in strange ways.
Both isotopes are forms of oxygen, always containing 8 protons in each atom. (Illustration: Sputnik)
Researcher Yosuke Kondo at Tokyo Institute of Technology explained in the August 30 issue of Nature that her team subjected certain elements to “extreme conditions” to create oxygen-28 and a slightly smaller isotope, oxygen-27.
Both isotopes are forms of oxygen, consistently containing 8 protons in each atom. However, an atom can have any number of neutrons without changing its chemical properties.
Previously, the maximum number of neutrons observed in an oxygen nucleus was 18. This isotope is known as oxygen-26 because it also contains 8 protons.
To form the new oxygen isotopes, Kondo’s team utilized the RIKEN Radioactive Isotope Beam Factory located in Saitama, Japan. They fired a beam of calcium-48 isotopes at a beryllium target to break apart calcium fragments and create lighter atoms. Among the products generated were fluorine-29 atoms, which contain 9 protons and 20 neutrons and are located next to oxygen on the periodic table.
The researchers then took these fluorine-29 atoms and broke them down along with a liquid hydrogen atom to transform fluorine into oxygen.
As a result, they created two distinct atoms through this process: oxygen-28 with 20 neutrons and oxygen-27 with 19 neutrons.
According to the article, what happened next puzzled the scientists. Although they expected oxygen-28 to be stable, it instead decayed and underwent spontaneous neutron emission.
This means it quickly released four neutrons and transformed into oxygen-24. Oxygen-27 also rapidly decayed, losing three neutrons to become oxygen-24.
The researchers initially believed that the two new forms of oxygen would exhibit stability based on the mathematical relationship governing the “shell” of particles in the nucleus, where multiples of 8 and 20 are considered “magic numbers” due to their high stability characteristics. Kondo’s team hoped that oxygen-28 would be stable because its neutron number is “double magic.”
For example, the form of oxygen we breathe here on Earth is oxygen-16, which is a multiple of 8 and extremely stable.
