Metallic Bonding Model

Steps:

• Recall metallic structure: positive ions form a lattice with delocalized valence electrons moving freely.
• Check option A: ions are positive, not negative, so incorrect.
• Check option B: delocalized electrons indeed move randomly through the lattice, matching the model.
• Eliminate C and D: malleability from sliding ion layers, not ion mobility; conduction by electron movement, not ions.

Why B is correct:

• In metallic bonding, valence electrons are delocalized and move randomly, as per the "sea of electrons" model, enabling electrical conductivity.

Why the others are wrong:

• A: Metal ions are positive cations, not negative anions.
• C: Ions form a fixed lattice; malleability arises from electron sea allowing layer sliding.
• D: Ions remain stationary; only electrons move under applied voltage.

Final answer: B