Question

List the steps in the process of calculating average atomic mass given data about the isotopes of an element.

Answer 1

The atomic weight or relative atomic mass of an element depends on the abundance of its isotopes. If you know the mass of the isotopes and the fractional abundance of the isotopes, you can calculate the element's atomic weight.

Solution to calculate atomic mass:

Atomic Mass= (mass of isotope) multiply to (%abundance) then add it to the (mass of another isotope) multiply to (%abundance), then divide all to 100%. See sample computations here.

Of interest, nineteen elements on the periodic table, including gold, cadmium, arsenic and aluminum are getting their atomic weights adjusted. The International Union of Pure and Applied Chemistry (IUPAC) announced that they've approved new weights for the elements thanks to more precise measurements and better calculations of the abundance of certain isotopes.