A certain atom has 26 protons, 26 electrons, and 30 neutrons. What is its mass number?

• A. 52
• B. 30
• C. 56
• D. 26

Answer: (C)

Verified step by step guidance

1. Identify the number of protons and neutrons in the atom. The problem states there are 26 protons and 30 neutrons.
2. Recall that the mass number of an atom is the sum of its protons and neutrons. This is because protons and neutrons contribute to the mass, while electrons have negligible mass.
3. Write the formula for mass number: \(\text{Mass Number} = \text{Number of Protons} + \text{Number of Neutrons}\).
4. Substitute the given values into the formula: \(\text{Mass Number} = 26 + 30\).
5. Add the numbers to find the mass number, which represents the total number of nucleons in the atom.