Types and Properties of Solids

Vocabulary flashcards covering key concepts about solids, including crystalline vs amorphous solids, and the main types of crystalline solids (ionic, metallic, covalent network, molecular) with example materials and properties.

Diamond

Hardest natural material on Earth.

Rock

A solid aggregate that forms the shape of mountains.

Iron

A dense metallic solid used in construction; magnetic.

Glass

Translucent, non-crystalline solid made from sand; used in windows.

Asphalt/Concrete

Materials used in road construction for hardness and durability.

Crystalline solids

Solids with highly ordered arrangement of particles (atoms, ions, molecules).

Amorphous solids

Solids lacking long-range order; do not have a definite melting point (e.g., glass, gels).

Ionic solids

Solids with ions held by electrostatic attractions; high melting points; conduct electricity when molten or dissolved; examples NaCl, Al2O3.

Metallic solids

Crystals of metals with a sea of delocalized electrons; metallic bonding; high conductivity; luster; malleable; ductile.

Covalent network solids

Solids with a 3D network of covalent bonds; very hard; high melting points; examples Diamond, SiO2, SiC; graphite has layered structure.

Molecular solids

Solids composed of neutral molecules held by intermolecular forces; melting points vary; examples H2O, CO2, C12H22O11.

Graphite

Planar sheets of covalent crystals held together by weaker forces; conducts electricity and is relatively soft.

Sodium chloride (NaCl)

Ionic solid; example of an ionic lattice.

Seven crystal systems

Cubic, Tetragonal, Hexagonal, Rhombohedral, Orthorhombic, Monoclinic, and Triclinic; defined by unit cell lengths and angles.

Isotropic

Physical properties are the same in all directions.

Anisotropic

Physical properties vary with direction.

Cleavage

When cut with a sharp edge, the surfaces of the two new halves are smooth.

Malleable

Can be hammered or pressed into shape without breaking.

Ductile

Can be drawn into wires without breaking.

Polar solids

Molecular solids with permanent dipole moments; generally higher melting points than nonpolar solids.

Non-polar solids

Molecular solids with no permanent dipole moment; generally lower melting points.

Two-dimensional solids

Solids with particle structure mainly extending in two dimensions.

Three-dimensional solids

Solids with particle structure extending in all three dimensions.