Calculate the atomic mass of an element from its isotopes. For elements with only one isotope, the value of the mass is the weight of that single isotope. Example is gold. Elements with 2 or more isotopes would require the mass of each isotope and the relative amounts of each isotope. Example would be silver. Use of a spectrophotometer indicates that isotope 1 of silver has a mass of 106.903 AMU and a sample of silver contains 51.35% of that isotope. Isotope 2 mass is 108.900 and the % is 48.65%. Determine that the atomic mass of silver is found
by multiplying the % of each isotope given in decimal units x the mass of each isotope and adding the sum.
(0.5135 x 106.92) + (0.4865 x 108.900) = 107.84 AMU