Which of the following is the number of neutrons in the most abundant isotope of iodine, iodine-127?

• A. 127
• B. 53
• C. 74
• D. 80

Answer: (C)

Verified step by step guidance

1. Identify the atomic number of iodine, which is the number of protons. For iodine, the atomic number is 53.
2. Understand that the isotope number (mass number) is the sum of protons and neutrons in the nucleus. For iodine-127, the mass number is 127.
3. Use the formula to find the number of neutrons: \(\text{Number of neutrons} = \text{Mass number} - \text{Atomic number}\).
4. Substitute the values for iodine-127: \(\text{Number of neutrons} = 127 - 53\).
5. Calculate the difference to find the number of neutrons in the most abundant isotope of iodine.