Question

which of these properties is the best one to use for identification of an element?
○ the number of neutrons in the atomic nucleus
○ the number of protons in the atomic nucleus
○ the number of isotopes that are formed by the element
○ the number of charges on ions of the element

Explanation:

• The number of neutrons can vary (isotopes) and doesn't uniquely identify an element.
• The atomic number (number of protons in the nucleus) is unique to each element, so it's the best identifier.
• The number of isotopes or ion charges can vary for an element and aren't unique identifiers.

Answer:

B. the number of protons in the atomic nucleus