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An example is calcium-40, with 20 neutrons and 20 protons, which is the heaviest stable isotope made of the same number of protons and neutrons. Both calcium-48 and nickel-48 are doubly magic because calcium-48 has 20 protons and 28 neutrons while nickel-48 has 28 protons and 20 neutrons. Calcium-48 is very neutron-rich for such a relatively ...
The term magic numbers is also used in the field of nuclear physics. In this context, magic numbers refer to a specific number of protons or neutrons that forms complete nucleon shells . [ 4 ]
Only five stable nuclides contain both an odd number of protons and an odd number of neutrons. The first four "odd–odd" nuclides occur in low mass nuclides, for which changing a proton to a neutron or vice versa would lead to a very lopsided proton–neutron ratio (2 1 H, 6 3 Li, 10 5 B, and 14 7 N; spins 1, 1, 3, 1).
[6] [27] Protons share the first six of these magic numbers, [28] and 126 has been predicted as a magic proton number since the 1940s. [29] Nuclides with a magic number of each—such as 16 O ( Z = 8, N = 8), 132 Sn ( Z = 50, N = 82), and 208 Pb ( Z = 82, N = 126)—are referred to as "doubly magic" and are more stable than nearby nuclides as a ...
These quantum shells correspond to a set of energy levels within the shell model of the nucleus; filled shells, such as the filled shell of 50 protons for tin, confers unusual stability on the nuclide. As in the case of tin, a magic number for Z, the atomic number, tends to increase the number of stable isotopes for the element.
The high number of isotopes is consistent with lead's atomic number being even. [g] Lead has a magic number of protons (82), for which the nuclear shell model accurately predicts an especially stable nucleus. [39] Lead-208 has 126 neutrons, another magic number, which may explain why lead-208 is extraordinarily stable. [39]
The number of protons in the nucleus is the defining property of an element, and is referred to as the atomic number (represented by the symbol Z). Since each element is identified by the number of protons in its nucleus, each element has its own atomic number, which determines the number of atomic electrons and consequently the chemical ...
Magic number (chemistry), number of atoms or molecules forming an exceptionally stable cluster Magic number (physics) , the number of nucleons that results in completely filled nuclear shells Magic number (programming) , either a unique identifier or a literal with unexplained meaning