Answer:
The answer to your question is 108.9 amu
Step-by-step explanation:
Data
Isotope 1 = 107Ag = 106.905 amu Abundance = 51.82%
Isotope 2 = 109Ag = ? Abundance = 100 - 51.82 = 48.18%
Average atomic mass = 107.868 amu
Formula
Average atomic mass = Isotope 1 x Abundance 1 + Isotope 2 x Abundance 2
Substitution
107.868 = (106.905 x 51.82) + (48.18 x Isotope 2)
Simplification
107.868 = 55.3982 + 48.18 Isotope 2
Solve for isotope 2
48.18 Isotope 2 = 107.868 - 55.398
48.18 Isotope 2 = 52.47
Isotope 2 = 52.47/48.18
Isotope 2 = 1.089 x 100
Isotope 2 = 108.9 amu