What is the atomic mass of the isotope of manganese (Mn) that contains 28 neutrons?

• A. 28
• B. 53
• C. 55
• D. 25

Answer: (B)

Verified step by step guidance

1. Recall that the atomic mass number (A) of an isotope is the sum of the number of protons (Z) and the number of neutrons (N) in the nucleus: \(A = Z + N\).
2. Identify the atomic number (Z) of manganese (Mn) from the periodic table. The atomic number corresponds to the number of protons in the nucleus.
3. Use the given number of neutrons (N = 28) and the atomic number (Z) of manganese to calculate the atomic mass number: \(A = Z + 28\).
4. Substitute the atomic number of manganese into the equation to find the atomic mass number of the isotope.
5. The resulting value of \(A\) is the atomic mass number of the manganese isotope with 28 neutrons.