tömegszámuk

Tömegszámuk is a Hungarian term referring to the mass numbers of a group of atomic nuclei. The singular form tömegszám denotes the mass number of a single nucleus, while the possessive plural form tömegszámuk means “their mass numbers.” The mass number, symbol A, is the total count of protons and neutrons in a nucleus.

The mass numberA is related to the atomic number Z (the number of protons) and the neutron number N by A = Z + N. It is an integer and differs between isotopes of the same element, even though the chemical element may have a fixed Z. In isotopic notation, the mass number appears as a superscript before the element symbol, for example, 14C (A = 14, Z = 6, N = 8) or 238U (A = 238, Z = 92, N = 146).

Tömegszámuk is used primarily to distinguish isotopes and to discuss nuclear properties that depend on the total number of nucleons, such as nuclear binding energy and decay schemes. It is important to note that the mass number is not the same as the atomic mass or atomic weight, which are related to the actual mass of the nucleus in unified atomic mass units and include contributions from binding energy and electron mass.

In summary, tömegszámuk refers to the set of mass numbers for a group of nuclides, while tömegszám denotes the mass number of an individual nucleus.