Which of the following is the number of neutrons in the most abundant isotope of lead, Pb-208?

• A. 208
• B. 126
• C. 82
• D. 146

Answer: (B)

Verified step by step guidance

1. Identify the atomic number (Z) of lead (Pb), which is the number of protons in the nucleus. For lead, Z = 82.
2. Recognize that the isotope notation Pb-208 indicates the mass number (A) is 208. The mass number is the total number of protons and neutrons in the nucleus.
3. Use the relationship between mass number, protons, and neutrons: \(A = Z + N\), where \(N\) is the number of neutrons.
4. Rearrange the formula to solve for the number of neutrons: \(N = A - Z\).
5. Substitute the known values into the equation: \(N = 208 - 82\), which gives the number of neutrons in the most abundant isotope of lead.