Question Detail
Question
The relative atomic mass of oxygen is 15.999. This is an average based on the abundance of its isotopes: ¹⁶O, ¹⁷O, and ¹⁸O. This value is closest to the mass number of which isotope?
Correct Answer
Option A is the correct answer.
Detailed Explanation
The relative atomic mass of oxygen is approximately 16 because ¹⁶O is by far the most abundant isotope (over 99%).
Hint
The average atomic mass is weighted toward the most abundant isotope.