tömegszámával

Tömegszámával is a Hungarian term that translates to "mass number" in English. It refers to the total number of protons and neutrons within the nucleus of an atom. This value is a fundamental property of an atom and distinguishes one isotope of an element from another. The mass number is often represented by the symbol 'A'. For example, a carbon atom with 6 protons and 6 neutrons has a mass number of 12, denoted as $^{12}$C. If the same carbon atom has 7 neutrons, its mass number becomes 13, and it is represented as $^{13}$C. While the number of protons determines the element's identity (atomic number, Z), the number of neutrons can vary, leading to different isotopes with the same chemical properties but different mass numbers and physical properties like density and radioactivity. The mass number is a key concept in nuclear physics and chemistry, crucial for understanding nuclear reactions, radioactive decay, and the composition of matter.