
Scientists have succeeded in creating a new type of tin atom with "magic" properties and in studying it in more detail than ever before.
The nuclei of normal tin atoms are made of 50 protons and 62 neutrons, creating a stable substance called tin-112 (or 112Sn, which is the chemical symbol for tin).
However, scientists can make a special version of tin with exactly 50 protons and 50 neutrons, creating a "doubly magic" atom with equal numbers of its nucleus' ingredients. In the new study, physicists created this tin-100 and analyzed its decay to reveal some of its spectacular properties.
The researchers, led by Christoph Hinke of Germany's Technische Universität München, reported their findings in the June 21 issue of the journal Nature.
"They have achieved a significant leap forward in the study of the heaviest 'symmetrical doubly magic' nucleus," Michigan State University's Daniel Bazin, who wasn't involved in the new study, wrote in an accompanying essay in Nature.
"Composed of 50 protons and 50 neutrons, this nucleus is drawing the attention of nuclear physicists around the globe because of its unique location in the nuclear landscape."
The nuclei of atoms have shells in which protons and neutrons can be arranged, similar to the shells of electrons that orbit the nucleus. The first nuclear shell fits two protons, or two neutrons, while the next shell fits six, and so on.
When a nucleus has enough protons or neutrons to fill a shell, it is especially stable, and scientists call these numbers "magic."
Thus, two protons is a magic number, as is eight, because with eight a nucleus can fill both its first and second proton shells of two and six, respectively.









