Question

1. a certain element exists as three different isotopes, 24.1% of all the isotopes have a mass of 75.23 amu, 48.7% have a mass of 74.61 amu, and 22.2% have a mass of 75.20 amu.

a. what is the average atomic mass of this element?
b. use your periodic table to determine which element this is.

1. an element exists as 4

Explanation:

Step1: Convert percentages to decimals

$24.1\%=0.241$, $48.7\% = 0.487$, $22.2\%=0.222$

Step2: Calculate the contribution of each isotope to the average atomic mass

For the first isotope: $0.241\times75.23 = 18.13043$
For the second isotope: $0.487\times74.61=36.33507$
For the third isotope: $0.222\times75.20 = 16.6944$

Step3: Sum up the contributions

$18.13043 + 36.33507+16.6944=71.16$

Answer:

a. The average atomic mass of the element is approximately $71.16$ amu.
b. Looking up the periodic - table, the element with an average atomic mass close to $71.16$ amu is Gallium (Ga) which has an average atomic mass of approximately $69.72$ amu. There may be some rounding differences in the calculations or the data provided in the problem.