The element silver has two naturally occurring isotopes, 107Ag and 109Ag. The atomic mass of 107Ag is 106.905. It makes up 51.82% of naturally occurring silver. The average atomic mass of silver is 107.868 amu. What is the atomic mass of 109AgThe element silver has two naturally occurring isotopes, 107Ag and 109Ag. The atomic mass of 107Ag is 106.905. It makes up 51.82% of naturally occurring silver. The average atomic mass of silver is 107.868 amu. What is the atomic mass of 109Ag?

The answer to your question is 108.9 amu

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

it's c. elements are placed in rows based on how may valencies electrons have.