Question

allotropes are _.
○ molecules bonded through the sharing of valence electron pairs
○ different structural modifications of an element
○ typically crystalline in structure
○ versions of an element having the same number of neutrons but differing numbers of protons

Explanation:

Allotropes are different structural forms of the same element. For example, carbon has allotropes like diamond and graphite. They have different physical properties due to different atomic - arrangements. The first option describes covalent bonding, the third option is not always true as not all allotropes are crystalline, and the fourth option describes isotopes (not allotropes).

Answer:

B. different structural modifications of an element