Answer
Atomic mass of the element = $96.056 amu$
Work Step by Step
Mass of Isotope 1 = $ 94.9 amu$
% abundance of Isotope 1 = $12.4\%$
Mass of Isotope 2 = $95.9 amu$
% abundance of Isotope 2 = $73.6\%$
Mass of Isotope 3 = $97.9amu$
% abundance of Isotope 3 = $14.0\%$
Atomic mass of an element is the weighted average of the masses of the constituent isotopes.
Therefore, atomic mass of the element is:
Atomic mass of the element = $0.124(94.9 amu) + 0.736(95.9 amu) + 0.14 (97.9 amu)$
Atomic mass of the element = $96.056amu$
