Solids and Modern Materials Vocabulary

Vocabulary flashcards covering solid-state structures, bonding models, alloys, polymers, and modern nanomaterials based on Chapter 12.

Metallic solids

Extended networks of atoms held together by metallic bonding (such as $\text{Cu}$ and $\text{Fe}$), characterized by a sea of collectively shared valence electrons.

Ionic solids

Extended networks of ions held together by mutual cation-anion electrostatic interactions (such as $\text{NaCl}$ and $\text{MgO}$).

Covalent-network solids

Extended networks of atoms joined throughout the solid by an extensive network of covalent bonds (such as $\text{C}$ and $\text{Si}$).

Molecular solids

Discrete molecules held together by weak intermolecular forces such as dispersion forces, dipole-dipole interactions, or hydrogen bonds (such as $\text{HBr}$ and $\text{H}_2\text{O}$).

Polymers

Molecules of high molecular weight formed by covalently joining smaller repeating units called monomers.

Nanomaterials

Crystalline compounds or particles with physical dimensions on the order of $1\,\text{nm}$ to $100\,\text{nm}$.

Crystalline solids

Solids in which constituent atoms, ions, or molecules are arranged in a regular, long-range repeating pattern.

Amorphous solids

Solids characterized by a distinct lack of long-range order in the spatial arrangement of their constituent atoms.

Unit cell

The smallest fundamental repeating unit that defines the size, shape, and spatial arrangement of atoms within a crystal lattice.

Crystal lattice

The three-dimensional geometric pattern of lattice points upon which a unit cell is based.

Lattice points

Specific positions defining the overall structure of a crystalline compound, where each position possesses an identical surrounding environment.

Seven basic 3-D crystal lattices

The seven fundamental three-dimensional crystal system lattices: cubic, tetragonal, orthorhombic, rhombohedral, hexagonal, monoclinic, and triclinic.

Centered cubic lattices

Cubic lattice classifications that possess lattice points at additional regular positions beyond the cell corners, such as body-centered cubic (one central lattice point) and face-centered cubic (one lattice point at each face center).

Alloys

Metallic materials containing more than one element that display the characteristic physical and chemical properties of metals.

Substitutional alloy

An alloy in which atoms of a secondary element directly replace host metal atoms of similar size in the crystal lattice.

Interstitial alloy

An alloy in which small secondary atoms occupy the interstitial gaps or voids between host metal atoms in the lattice structure.

Electron-sea model

A metallic bonding model representing metal cations suspended in a mobile, delocalized sea of valence electrons.

Addition polymers

Polymers formed when unsaturated monomer double bonds break open to form two new single bonds linking adjacent monomer units without producing small molecule byproducts.

Condensation polymers

Polymers formed when functional groups of two different monomer molecules join together with the simultaneous elimination of a small molecule such as $\text{H}_2\text{O}$.

Copolymers

Polymers synthesized by combining two or more structurally distinct types of monomer species.

Polymer crystallinity

Regions of short-range structural ordering within a polymer matrix that increase density, hardness, melting point, heat resistance, and chemical stability.

Vulcanization

A chemical cross-linking process in which polymer chains are joined together by short chains of sulfur atoms to increase strength, elasticity, and mechanical stability.

Quantum dots

Semiconductor nanoparticles measuring approximately $1\,\text{nm}$ to $10\,\text{nm}$ in diameter whose band gap energy and radiation absorption/emission vary with size.

Buckminsterfullerene

An allotrope of carbon composed of discrete spherical $\text{C}_{60}$ molecules arranged in a hollow geodesic dome structure, commonly known as buckyballs.

Carbon nanotubes

Tubular carbon nanostructures derived from rolled graphene sheets that demonstrate exceptional structural strength and can act as conductors or semiconductors without doping.

Graphene

A single two-dimensional layer of carbon atoms tightly bound in a hexagonal honeycomb crystal lattice.