Researchers have come one step closer to understanding unstable atomic nuclei.
The protons and neutrons inside the atomic nucleus exhibit shell structures in a manner similar to electrons in an atom. For naturally stable nuclei, these nuclear shells fill completely when the number of protons or the number of neutrons is equal to the 'magic' numbers 2, 8, 20, 28, 50, 82 or 126. But not always. For exotic nuclei, 28 is not a magic number of neutrons. Traditional magic numbers, which were once thought to be common for all nuclei, can change in unstable, radioactive nuclei that have a large imbalance of protons and neutrons.