Question

what makes each element unique?
multiple choice
number of bonds formed
physical and chemical properties
quantity of the element in the universe
number of neutrons

Explanation:

Each element has distinct physical (like melting point) and chemical (like reactivity) properties. The number of bonds formed can vary for an element (e.g., carbon can form single, double, or triple bonds). The quantity of an element in the universe doesn't define its uniqueness. The number of neutrons can vary (isotopes), but the element's identity is mainly from protons. Physical and chemical properties are unique to each element.

Answer:

physical and chemical properties