Fe-54 = 5.845% Fe-56 = 91.754%
Fe-58 = 2.119%

(Please help)
Calculate the average atomic mass/ given their percent abundance

55.768

Explanation:

The following information is given in this question:

Fe-54 = 5.845%

Fe-56 = 91.754%

Fe-58 = 2.119%

First, we convert from percentage abundance to decimal abundance

Fe-54 = 5.845% = 0.05845

Fe-56 = 91.754% = 0.91754

Fe-58 = 2.119% = 0.02119

To find the average atomic mass of iron (Fe), we multiply each isotopes' decimal abundance by its mass no and find the sum as follows:

Average atomic mass = (0.05845 × 54) + (0.91754 × 56) + (0.02119 × 58)

Average atomic mass = 3.1563 + 51.38224 + 1.22902

Average atomic mass = 55.768