What is the mass number for an atom of xenon containing 54 protons and 76 neutrons?

• A. 54
• B. 76
• C. 122
• D. 130

Answer: (D)

Verified step by step guidance

1. Identify the number of protons and neutrons given in the problem. Here, the atom has 54 protons and 76 neutrons.
2. Recall that the mass number (A) of an atom is the total number of protons and neutrons in its nucleus.
3. Use the formula for mass number: \(A = Z + N\), where \(Z\) is the number of protons and \(N\) is the number of neutrons.
4. Substitute the given values into the formula: \(A = 54 + 76\).
5. Add the numbers to find the mass number, which represents the total nucleons in the atom.