Two natural isotopes exist for silver.51.83% of the atoms have a mass of 106.90509 u,and the remaining fraction has a mass of 108.9047 u.Calculate the atomic mass of silver.

Question

Quizplus · Accepted Answer

The atomic mass is calculated as a weighted average of the masses of the isotopes, where the weights are the relative abundances of each isotope. 
Calculating the weighted average for the two isotopes of silver:

Atomic mass = (0.5183 × 106.90509 u) + (0.4817 × 108.9047 u) 
Atomic mass = 55.97 u

Therefore, the closest option to this calculated atomic mass value is D) 107.87 u.

Two Natural Isotopes Exist for Silver