Examkin

Question

Difficulty: MediumMetallic Bonding and Properties of Metals

In solid-state chemistry, the distinct physical behaviors of metals arise directly from the structural characteristics of metallic bonds. Match each observable metallic property or behavior on the left with its corresponding atomic-scale explanation on the right.

  • High electrical conductivity of solid metalsUnconfined valence electrons drifting directionally when exposed to an applied potential difference
  • High malleability and ductility without fractureNon-directional electrostatic attractions allowing cation layers to slide past each other while maintaining cohesive forces
  • Significantly higher melting point of iron compared to sodiumContribution of delocalized inner d-orbital electrons alongside s-electrons, strengthening cohesive metallic bonding
  • Lustrous and shiny reflective appearance of freshly cut metal surfacesOscillation of free valence electrons absorbing and rapidly re-emitting incident photons of light

Answer

High electrical conductivity corresponds to unconfined valence electrons drifting directionally under an applied potential difference. High malleability and ductility correspond to non-directional electrostatic attractions allowing cation layers to slide past each other while maintaining cohesive forces. Higher melting point of iron compared to sodium corresponds to the contribution of delocalized d-orbital electrons alongside s-electrons. Lustrous reflective appearance corresponds to the oscillation of free valence electrons absorbing and rapidly re-emitting incident photons.
High electrical conductivity is explained by the movement of unconfined valence electrons drifting directionally when a potential difference is applied. High malleability and ductility stem from non-directional electrostatic forces allowing metal cation planes to slide over each other without breaking cohesive bonds. The higher melting point of transition metals like iron compared to alkali metals like sodium is caused by extra binding strength provided by delocalized d-orbital electrons in addition to s-electrons. Metallic luster is caused by mobile valence electrons absorbing incident light energy and immediately re-emitting it.

Step-by-Step Solution

1
Analyze the microscopic origin of electrical conduction in metallic crystals.
Electrical conduction requires mobile charge carriers. In metals, delocalized valence electrons move freely across the lattice under an electric potential.
Relates macroscopic electric current to electron mobility.
2
Analyze how mechanical force affects metal cation layers.
Deformation causes layers of cations to slip over each other. Because metallic bonds are non-directional, the electron sea adjusts instantly to keep the lattice bound without brittle cleavage.
Explains malleability and ductility via non-directional bonding.
3
Compare the bonding strength of alkali metals versus transition metals.
Sodium donates only one s-electron per atom into the sea, whereas iron donates both s and unpaired inner d-electrons, greatly increasing the electrostatic cohesive energy and melting point.
Explains variation in thermal resistance and hardness across different metals.
4
Analyze the interaction between light waves and delocalized electron clouds.
Mobile surface electrons readily absorb light energy and oscillate, promptly re-radiating light photons to generate a high spectral reflectance (luster).
Connects optical reflectivity to electron sea excitation.

Key Concept

Electron Sea Model and Metal Property Mechanisms
Rate this question

Topics

Metallic Bonding and Properties of Metals

More questions from this topic