What is the effect of delocalized electrons on electrical conductivity?
Delocalized electrons allow metals to conduct electricity because they can move freely and carry charge.
What is the effect of adding carbon to iron to make steel?
The carbon atoms increase the density of the structure, making the steel stronger and harder.
What is the effect of similar sized atoms in substitutional alloys on electrical conductivity?
Substitutional alloys often maintain good electrical conductivity because the delocalized electrons can still move relatively freely.
What is the effect of strong metallic bonds on melting point?
Strong metallic bonds require a lot of energy to break, resulting in high melting points.
What is the effect of mobile electrons on the appearance of metals?
Mobile electrons interact with light, causing metals to have a shiny appearance.
Define metallic bonding.
Bonding resulting from the attraction between positively charged metal ions and a 'sea' of delocalized electrons.
What are delocalized electrons?
Electrons that are not associated with a single atom or bond, and are free to move throughout the metallic structure.
Define an alloy.
A mixture of two or more elements, at least one of which is a metal, creating a substance with enhanced properties.
What is an interstitial alloy?
An alloy formed when smaller atoms fill the spaces between larger atoms in a metallic lattice.
What is a substitutional alloy?
An alloy formed when atoms of one element are replaced by atoms of another element of similar size in a metallic lattice.
Define malleability.
The ability of a metal to be hammered or pressed into shape without breaking or cracking.
Define ductility.
The ability of a metal to be drawn into wires without breaking.
Compare interstitial and substitutional alloys.
Interstitial: Smaller atoms inserted into gaps. Substitutional: Atoms replaced by similar-sized atoms.
Compare metallic and ionic solids.
Metallic: Delocalized electrons, conductive, malleable. Ionic: Electrostatic attractions, brittle, non-conductive (solid).
Compare the conductivity of metals and ionic compounds.
Metals: Good conductors due to mobile electrons. Ionic compounds: Poor conductors in solid-state, good when molten/aqueous.
Compare the hardness of interstitial and substitutional alloys.
Interstitial Alloys: Generally harder and stronger. Substitutional Alloys: Can be harder, but often retain good conductivity.
Compare the melting points of metals and molecular solids.
Metals: Typically have high melting points due to strong metallic bonds. Molecular Solids: Typically have low melting points due to weak intermolecular forces.
