Chem
posted by Rebekah .
(b) If the natural abundance of Ag107 is 51.84%, what is the natural abundance of Ag109?
%
(c) If the mass of Ag107 is 106.905, what is the mass of Ag109?
amu
I really need help. Can u say the answer then explain how you got it?
Thanks:)

Oops I just need c

106.905(0.5184) + massAg109(10.5184) = mass Ag from periodic table.
Solve for the only unknown which is mass Ag 109.
Remember the isotopes are averaged to obtain the atomic mass found in the periodic table. 
THE FOLLOWING SOLUTIONS AREMIXED TOGETHER: 121mL OF 1.54 M AgNO3 AND 45mL OF 1.07 M K2SO4
CALCULATE THE MOLAR CONCENTRATION OF Ag+ IONS IN THE FINAL SOLUTION