An element has three naturally occurring isotopes with the following masses and abundances: Isotopic Mass (amu) Fractional

Question:

An element has three naturally occurring isotopes with the following masses and abundances:
Isotopic Mass (amu) Fractional Abundance
38.964……………………………… 0.9326
39.964……………………………… 1.000 × 10–4
40.962……………………………… 0.0673
Calculate the atomic mass of this element. What is the identity of the element?