Question

calculate the average atomic mass for oxygen given the following;
isotope %abundance relative mass mass contribution
o-16 99.7572 15.9949146 amu (1)(15.9949146 amu) = 2 amu
o-17 0.0381 16.9991317 amu (3)(16.9991317 amu) = 4 amu
o-18 0.20514 17.9991611 amu (5)(17.9991611 amu) = 6 amu
7 amu
first we need to convert the % abundance into abundance by dividing by 100.
thus, 99.7572% becomes:
99.7572
------- = 8
100
a. 15.9995 b. 15.9994791 c. 0.0020514 d. 0.000381
e. 0.997572 f. 99.7572. g. 0.03692348 h. 0.0064767
i. 15.956079 j 1.5956079

Explanation:

Step1: Convert % to decimal

To convert 99.7572% to a decimal, we divide by 100: $\frac{99.7572}{100}$.

Step2: Calculate the value

Performing the division: $\frac{99.7572}{100} = 0.997572$.

Answer:

E. 0.997572