A 20.0-gram sample of magnesium oxide contains 16.2 grams of magnesium. What is the percent of oxygen by mass in this compound?

A 20.0-gram sample of magnesium oxide contains 16.2 grams of magnesium. What is the percent of oxygen by mass in this compound?

A 20.0-gram sample of magnesium oxide contains 16.2 grams of magnesium. What is the percent of oxygen by mass in this compound?




a. 81%
b. 19%
c. 43%
d. 1.9%




Answer: B