calculate the average atomic mass of element x in which the first isotope found in 28.5% abundance weighs 200.0 amu and the other isotope weighs 220.0 amu.
See Bob Pursley's answer above.
To calculate the average atomic mass of an element, you need to consider the abundance and mass of each isotope of that element.
Given:
- The first isotope has an abundance of 28.5% and a mass of 200.0 amu.
- The second isotope has an abundance of (100% - 28.5% =) 71.5% and a mass of 220.0 amu.
To calculate the average atomic mass, follow these steps:
Step 1: Convert the abundances to decimal form.
Abundance of first isotope: 28.5% = 0.285 (decimal)
Abundance of second isotope: 71.5% = 0.715 (decimal)
Step 2: Multiply the mass of each isotope by its respective abundance.
Mass of first isotope: 200.0 amu × 0.285 = 57.0 amu (rounded to one decimal place)
Mass of second isotope: 220.0 amu × 0.715 = 157.3 amu (rounded to one decimal place)
Step 3: Add the mass contributions from each isotope to find the average atomic mass.
Average atomic mass = Mass of first isotope + Mass of second isotope
Average atomic mass = 57.0 amu + 157.3 amu = 214.3 amu (rounded to one decimal place)
Therefore, the average atomic mass of element X is approximately 214.3 amu.