Question

Please Help Me on this!!!! I'll Mark Brainliest!!!!! Thanks!!!!!!

Answer 1

Answer:

15.999amu

Explanation:

There is way more O16 than any other, so O17 and O18 affect it very little.

Answer 2

Answer:

The answer is 15.999 amu

Explanation:

Data:

mO16 = 15.995 amu

mO17 = 16.999 amu

mO18 = 17.999 amu

%O16 = 99.757%

%O17 = 0.038%

%O18 = 0.205%

The molecular mass of oxygen is going to be equal to:

$mO = \frac{(mO16xpercentO16)+(mO17xpercentO17)+(mO18xpercentO18)}{100}$

replacing, we have:

$mO = \frac{(15.995x99.757)+(16.999x0.038)+(17.999x0.205)}{100} = 15.999489 amu$

this is approximately 15.999 amu