Question

In which of the following substances does sharing of electrons between two atoms occur?

a) Ar
b) KCl
c) Au
d) Cr2O7^2–

Answer 1

The sharing of electrons between two atoms occurs in Cr2O72–, which is a polyatomic ion with covalent bonds.

Step-by-step explanation:

The sharing of electrons between two atoms occurs in a covalent bond. Looking at the given substances, Argon (Ar) is a noble gas and thus, does not typically form bonds as it has a complete valence shell. Potassium Chloride (KCl) is an ionic compound where electrons are transferred, not shared. Gold (Au) is a metal and typically forms metallic bonds, which involve a sea of delocalized electrons around positive metal ions, not the sharing of electrons between two particular atoms. The dichromate ion (Cr2O72–) is a polyatomic ion in which there is a sharing of electrons between chromium and oxygen atoms, reflected in the possession of covalent bonds within its structure. Hence, the substance in which sharing of electrons occurs is Cr2O72–.