Question

Element B consists of three different isotopes X, Y, and Z. Isotope X has a mass number of 44 and accounts for 50% of naturally occurring B. Isotope Y has a mass number of 48 and accounts for 25% of naturally occurring B. Isotope Z has a mass number of 50 and accounts for 25% of naturally occurring B. The average atomic weight of element B is amu.

Answer 1

The average atomic weight is going to be equal to the sum of the mass of each isotope multiplied by its relative abundance.

Average atomic mass = f1M1 + f2M2 + ... + fnMn where f is the fraction representing the natural abundance of the isotope and M is the mass number (weight) of the isotope.

Average atomic mass = (0.50 ⋅ 44 amu) + (0.25 ⋅ 48 amu)+ (..............) = ? amu