Which of the following oxygen isotopes is the most abundant in nature?

• A. O-15
• B. O-18
• C. O-16
• D. O-17

Answer: (C)

Verified step by step guidance

1. Understand that isotopes are atoms of the same element with different numbers of neutrons, which means they have the same number of protons but different mass numbers.
2. Recognize that oxygen has several isotopes, commonly O-16, O-17, and O-18, where the number indicates the total number of protons and neutrons.
3. Recall that the most abundant isotope of an element in nature is the one that occurs in the highest natural abundance percentage.
4. Know that O-16 is the most abundant oxygen isotope naturally, making up about 99.76% of oxygen found on Earth, while O-17 and O-18 are much less common, and O-15 is a radioactive isotope with a very short half-life and is not naturally abundant.
5. Therefore, by comparing natural abundances, conclude that O-16 is the most abundant oxygen isotope in nature.