Final answer:
The average atomic mass of an element is the sum of the products of each isotope's mass number and relative abundance. It reflects the weighted average of all isotopes present in nature. Atomic mass is measured in atomic mass units (amu) and helps understanding an element's mass on the periodic table.
Step-by-step explanation:
The average atomic mass for an element is calculated as the weighted average of the atomic masses of the element's naturally occurring isotopes. To determine this value, one multiplies the mass of each isotope by its relative abundance (expressed as a decimal), and then sums these products.
An element’s atomic mass is essentially a statistical average because it accounts for the masses of all the different isotopes and their abundances in nature. Atomic Mass Units (amu) are used to express these masses. For instance, if an element has two main isotopes with masses of 10 amu and 11 amu, found in nature at 50% abundance each, its atomic mass would be calculated as (0.5 * 10) + (0.5 * 11) = 10.5 amu.