Which property makes one element distinct from another?

• A. The number of neutrons in the nucleus
• B. The number of protons in the nucleus
• C. The atomic mass of the element
• D. The number of electrons in the outer shell

Answer: (B)

Verified step by step guidance

1. Understand that elements are defined by their atomic structure, specifically the particles in their nucleus and electron configuration.
2. Recall that the number of protons in the nucleus is called the atomic number, which uniquely identifies an element.
3. Recognize that while neutrons affect isotopes and atomic mass affects the overall weight, they do not change the element's identity.
4. Note that the number of electrons in the outer shell influences chemical behavior but does not define the element itself.
5. Conclude that the property that makes one element distinct from another is the number of protons in the nucleus, or the atomic number.