Element X consists of two major isotopes with the following percent abundances and atomic masses: 35.0% and 85.0 amu; and 65.0% and 84.0 amu. Calculate the average atomic mass of element X.

0.35(85) + (0.65)(84) = ?

Solve for ?

To calculate the average atomic mass of element X, we need to consider the percent abundances and atomic masses of its isotopes. The average atomic mass is determined by summing the products of the percent abundance and atomic mass of each isotope.

Step 1: Convert the percent abundances to decimal form by dividing each percentage by 100.
- The first isotope has a percent abundance of 35.0%, so we convert it to 0.35.
- The second isotope has a percent abundance of 65.0%, so we convert it to 0.65.

Step 2: Multiply each isotope's percent abundance by its atomic mass.
- For the first isotope: 0.35 x 85.0 amu = 29.75 amu.
- For the second isotope: 0.65 x 84.0 amu = 54.6 amu.

Step 3: Sum the products obtained in step 2.
- 29.75 amu + 54.6 amu = 84.35 amu.

Therefore, the average atomic mass of element X is 84.35 amu.