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In this article, we will learn how to calculate mass number(A) but first off, lets define it. Mass number is an integer equal to the sum of the number of protons and neutrons of an atomic nucleus. Neutrons are the subatomic particles present in atomic nuclei like protons.
The mass number is defined as the total number of protons and neutrons in an atom. It can be calculated by adding the number of neutrons and the number of protons (atomic number) together. Mass number = atomic number + number of neutrons. Consider Table \(\PageIndex{1}\) below that shows data from the first six elements of the periodic table.
The atom calculator is a tool for calculating the atomic number and the mass number based on the number of atom components - protons, neutrons, and electrons (or vice versa). In addition, you can define the charge of ions with known numbers of protons and electrons.
The mass number gives an estimate of the isotopic mass measured in atomic mass units (u). For 12 C, the isotopic mass is exactly 12, since the atomic mass unit is defined as 1/12 of the mass of 12 C. For other isotopes, the isotopic mass is usually within 0.1 u of the mass number.
Calculate the mass number of each isotope by adding together the numbers of protons and neutrons. Give the symbol of each isotope with the mass number as the superscript and the number of protons as the subscript, both written to the left of the symbol of the element.
26 cze 2023 · Determine the number of protons, neutrons, and electrons in an atom. Identify the charge and relative mass of subatomic particles. Label the location of subatomic particles in the atom. Determine the mass of an atom based on its subatomic particles. Write A/Z and symbol-mass format for an atom.
