Which element has the greatest number of protons in its nucleus?

• A. Chlorine (Cl)
• B. Neon (Ne)
• C. Oxygen (O)
• D. Sodium (Na)

Answer: (A)

Verified step by step guidance

1. Understand that the number of protons in an element's nucleus is called the atomic number, which uniquely identifies each element.
2. Recall or look up the atomic numbers of the given elements: Neon (Ne), Oxygen (O), Sodium (Na), and Chlorine (Cl).
3. Compare the atomic numbers of these elements to determine which one has the greatest number of protons.
4. Remember that the element with the highest atomic number among the options will have the greatest number of protons.
5. Conclude that the element with the greatest atomic number is the one with the greatest number of protons in its nucleus.