Question

In which substance does sharing of electrons between two atoms occur?

Responses

Cr2O7 2−
uppercase C lowercase r subscript 2 end subscript uppercase O subscript 7 end subscript superscript 2 minus end superscript

Ar
uppercase A lowercase r

Au
uppercase A lowercase u

KCl

Answer 1

Cr2O7^2−

Explanation: "Sharing of electrons between two atoms" describes covalent bonding. In the dichromate ion (Cr2O7^2−) the Cr–O bonds are covalent (with resonance). Ar is monatomic (no bonds), KCl is ionic (electron transfer), and Au exhibits metallic bonding (delocalized electrons, not a two‑atom covalent bond).