Respuesta :

yes I do

so u need to find the amount of grams total and the individual amount of grams.

so 40+40+52+16+16+16+16=196g  (I got the numbers from the periodic table)

K- 80g

Cr-52g

O-64g

since you are solving for oxygen, you would only use the oxygen part so...

64g/196g=32.9%

32.9% is the answer

hope this helps! if it doesn't, let me know in the comments! have a blessed day!