Which of the following is closest to the natural abundance of the isotope Br-79?

• A. 23.1%
• B. 75.4%
• C. 10.8%
• D. 50.7%

Answer: (D)

Verified step by step guidance

1. Understand that natural abundance refers to the percentage of a specific isotope found naturally in a sample of an element.
2. Recall that bromine (Br) has two main isotopes: Br-79 and Br-81, and their natural abundances must add up to 100%.
3. Recognize that the natural abundance of Br-79 is approximately half of the total bromine isotopes, so it should be close to 50%.
4. Compare the given options (23.1%, 75.4%, 10.8%) to the expected value near 50%, and identify which is closest.
5. Confirm that the correct natural abundance of Br-79 is about 50.7%, which is not listed among the options, indicating the answer should be closest to this value.