Question

q6. choose the correct answer.

a sample of element x contains 90 percent ³⁵x atoms, 8.0 percent ³⁷x atoms, and 2.0 percent ³²x atoms. the average isotopic mass is closest to

a. 32 b. 35 c. 37 d. 38

q7. choose the correct answer.

Explanation:

Step1: Calculate the contribution of each isotope

The formula for average isotopic mass is \(\sum(\text{isotopic mass}\times\text{abundance})\).
For \(^{35}X\): \(35\times0.90 = 31.5\)
For \(^{37}X\): \(37\times0.08=2.96\)
For \(^{32}X\): \(32\times0.02 = 0.64\)

Step2: Sum up the contributions

\(31.5+2.96 + 0.64=35.1\)

Answer:

B. 35