Which of the following correctly states the number of protons and neutrons in an atom of iron-56?

• A. 26 protons and 56 neutrons
• B. 26 protons and 30 neutrons
• C. 28 protons and 28 neutrons
• D. 30 protons and 26 neutrons

Answer: (B)

Verified step by step guidance

1. Identify the atomic number of iron, which represents the number of protons in the atom. For iron (Fe), the atomic number is 26, so it has 26 protons.
2. Understand that the number after the element name (56 in iron-56) is the mass number, which is the total number of protons and neutrons in the nucleus.
3. Use the formula to find the number of neutrons: \(\text{Number of neutrons} = \text{Mass number} - \text{Number of protons}\).
4. Substitute the known values into the formula: \(\text{Number of neutrons} = 56 - 26\).
5. Calculate the difference to find the number of neutrons, which will help you select the correct option stating the number of protons and neutrons.