Question

unit 3-part ii: molecules and bonding
define sea of electrons:

why are metallic compounds malleable and ductile?

why are metallic compounds good conductors of heat and electricity?

why do ionic compounds only conduct electricity when dissolved in water?

Explanation:

1. Sea of Electrons: This is a model describing metallic bonding, where valence electrons of metal atoms are delocalized, moving freely between positively charged metal cations.
2. Metallic malleability/ductility: The delocalized electron sea allows metal cation layers to slide past one another without breaking the overall bonding, as the electrons redistribute to maintain attraction.
3. Metallic conductivity: Delocalized, freely moving electrons can carry electric charge (for electricity) and kinetic energy (for heat) throughout the metal structure.
4. Ionic compound conductivity: Solid ionic compounds have fixed, locked ions that cannot carry charge. Dissolving in water breaks the lattice, freeing ions to move and conduct electric current.

Answer:

1. Sea of Electrons: A model for metallic bonding where valence electrons of metal atoms are delocalized, forming a "sea" of freely moving electrons surrounding positively charged metal cations.
2. Metallic compounds are malleable and ductile because their delocalized electron sea allows layers of positive metal ions to slide past each other without breaking the overall metallic bonding.
3. Metallic compounds are good conductors of heat and electricity because their delocalized, freely moving electrons can carry electrical charge and thermal energy throughout the material.
4. Ionic compounds only conduct electricity when dissolved in water because in their solid state, ions are locked in a rigid lattice and cannot move to carry charge; dissolving breaks the lattice, releasing mobile ions that can conduct electric current.