Calculate the atomic mass of silver if silver has two naturally occurring isotopes with the following masses and natural abundances:
Ag-107 106.90509 amu 51.84%
Ag-109 108.90476 amu 48.46%
A)107.90 amu
B)108.00 amu
C)107.79 amu
D)108.32 amu
E)108.19 amu

Question

Calculate the atomic mass of silver if silver has two naturally occurring isotopes with the following masses and natural abundances: 
Ag-107 106.90509 amu 51.84%
Ag-109 108.90476 amu 48.46%
A)107.90 amu
B)108.00 amu
C)107.79 amu
D)108.32 amu
E)108.19 amu

Quizplus · Accepted Answer

The atomic mass of an element is the weighted average of the masses of its isotopes, taking into account their natural abundances. The atomic mass of silver can be calculated as follows:Atomic mass = (mass of Ag-107 x abundance of Ag-107) + (mass of Ag-109 x abundance of Ag-109)= (106.90509 amu x 51.84%) + (108.90476 amu x 48.46%)= 107.90 amu (rounded to two decimal places)Therefore, the atomic mass of silver is 107.90 amu, which corresponds to choice E.

Calculate the Atomic Mass of Silver If Silver Has Two