# 3 - Atomic Structure Calculations of atomic mass
The three stable isotopes of silicon have masses and natural abundances
as follows. Calculate the atomic mass.
There are two stable isotopes of bromine. Isotope A has a mass of 78.918336
amu and isotope B has a mass of 80.916289 amu.
Determine the natural abundance of the isotopes, and report the answer
to three significant figures.
Write the symbol for the two isotopes.
There are two naturally occurring isotopes of silver, 107Ag
and 109Ag. The atomic mass of silver is 107.87 amu, with 51.82%
of the atoms being 107Ag. The mass of an atom of 107Ag
is 106.9 amu. What is the mass, in amu, of an atom of 109Ag.