Question

which of the following best describes the arrangement of electrons in a metallic bond?
a. electrons are transferred from one atom to another.
b. electrons exist as shared electron pairs between neutral atoms.
c. electrons are delocalized in a \sea of electrons\ and are shared among the positively charged metal ions.
d. electrons are shared unequally, creating a bond with partial positive and negative poles.

atoms of this substance are tightly packed in a crystal lattice. the bonds between atoms are strong and omnidirectional, and are caused by the availability of electrons moving freely in conduction bands. which of the following substances could be described in this way?

a. diamond
b. sodium chloride
c. gold
d. water ice

Explanation:

First Question (Metallic Bond Electron Arrangement)

• Option A: Electron transfer is ionic bonding, not metallic. Eliminate.
• Option B: Shared electron pairs between neutral atoms describe covalent bonding (e.g., in molecules like \(H_2\)). Eliminate.
• Option C: Metallic bonds involve delocalized electrons (sea of electrons) shared among positive metal ions. This matches the definition of metallic bonding.
• Option D: Unequal sharing with partial poles is a polar covalent bond (e.g., in \(H_2O\)). Eliminate.

• The description (tightly packed crystal lattice, strong omnidirectional bonds, free - moving electrons in conduction bands) matches metallic bonding.
• Option A: Diamond has covalent network bonding (electrons are localized in covalent bonds, no free - moving electrons for conduction in the same way). Eliminate.
• Option B: Sodium chloride (\(NaCl\)) has ionic bonding (ions are held by electrostatic forces, no free - moving electrons in conduction bands as in metals). Eliminate.
• Option C: Gold is a metal. It has metallic bonding with delocalized electrons in a sea of electrons, and its atoms are in a crystal lattice with strong, omnidirectional bonds. This fits the description.
• Option D: Water ice (\(H_2O(s)\)) has hydrogen bonding and intermolecular forces (covalent bonds within molecules, but the overall structure and bonding do not match the description). Eliminate.

Answer:

C. Electrons are delocalized in a "sea of electrons" and are shared among the positively charged metal ions.

Second Question (Substance with Described Bonding)