Manganese has an atomic number of 25 and a mass number of 55. How many neutrons does a typical atom of manganese contain?

• A. 55
• B. 25
• C. 80
• D. 30

Answer: (D)

Verified step by step guidance

1. Identify the atomic number (Z) of manganese, which is the number of protons in the nucleus. For manganese, Z = 25.
2. Identify the mass number (A) of manganese, which is the total number of protons and neutrons in the nucleus. For manganese, A = 55.
3. Recall 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: \(N = 55 - 25\) to find the number of neutrons in a typical manganese atom.