How Do You Find Relative Atomic Mass?
The relative atomic mass is the ratio of an atom mass to 1/12 of the mass of an atom of carbon-12 (isotope 12). Isotopes have the same number of protons and hence the same atomic number, but they vary in the numbers of neutrons. For instance, the isotope carbon-12 has six protons and six neutrons while the carbon-13 isotope has six protons, but seven neutrons. To find out the relative atomic mass of an element, it is necessary to take into account its isotope composition. As an example, find this mass for silicon (Si) that has the atomic number of 14. Step 1 Follow the link to open the International Union of Pure and Applied Chemistry (IUPAC) Report “Isotopic compositions of the elements 1997.” Step 2 Find the element of interest in Table 1 of the IUPAC report. Element isotope masses and the respective isotope compositions are given in the third and ninth columns of the table. In our example, silicon (Si) has three isotopes: Si (isotope 28) — 92.230 percent Si (isotope 29) — 4.683 pe
The relative atomic mass is the ratio of an atom mass to 1/12 of the mass of an atom of carbon-12 (isotope 12). Isotopes have the same number of protons and hence the same atomic number, but they vary in the numbers of neutrons. For instance, the isotope carbon-12 has six protons and six neutrons while the carbon-13 isotope has six protons, but seven neutrons. To find out the relative atomic mass of an element, it is necessary to take into account its isotope composition. As an example, find this mass for silicon (Si) that has the atomic number of 14. Follow the link to open the International Union of Pure and Applied Chemistry (IUPAC) Report “Isotopic compositions of the elements 1997.” Find the element of interest in Table 1 of the IUPAC report. Element isotope masses and the respective isotope compositions are given in the third and ninth columns of the table. In our example, silicon (Si) has three isotopes: Si (isotope 28) — 92.230 percent Si (isotope 29) — 4.683 percent Si (isot
