Question

1. calculate the average atomic mass of oxygen using the information in the table below.

isotope	oxygen-16	oxygen-17	oxygen-18
percent abundance	99.759%	0.037%	0.204%

Explanation:

Step1: Convert percentages to decimals

$99.759\% = 0.99759$, $0.037\%=0.00037$, $0.204\% = 0.00204$

Step2: Calculate weighted - mass for Oxygen - 16

$15.995\times0.99759 = 15.96394205$

Step3: Calculate weighted - mass for Oxygen - 17

$16.995\times0.00037 = 0.00628815$

Step4: Calculate weighted - mass for Oxygen - 18

$17.999\times0.00204 = 0.03671796$

Step5: Sum up the weighted - masses

$15.96394205+0.00628815 + 0.03671796=15.99994816\approx15.9999$ amu

Answer:

$15.9999$ amu