Intermolecular Forces and Properties (IMFs, States of Matter, and Solids)

Vocabulary practice flashcards covering intermolecular forces, properties of liquids, phase changes, and types of crystalline, amorphous, and network solids.

Surface tension

The resistance of a liquid to increase its surface area, which pulls the liquid into a droplet.

Capillary action

The spontaneous rising of a liquid in a narrow tube resulting from cohesive forces and adhesive forces.

Concave meniscus

The curved upper surface of a liquid column that forms when adhesive forces are greater than cohesive forces.

Convex meniscus

The curved upper surface of a liquid column that forms when cohesive forces are greater than adhesive forces.

Viscosity

The resistance of a liquid to flow, which increases with stronger intermolecular forces and more complex molecules.

Vapor pressure

The pressure exerted by the vapor that forms above a liquid, varying with intermolecular interactions and temperature.

Normal melting point

The temperature at which the solid and liquid states have the same vapor pressure where total pressure is $1\,\text{atm}$.

Normal boiling point

The temperature at which the vapor pressure of a liquid is exactly $1\,\text{atm}$.

Sublimation

The direct transition of a substance from the solid phase to the gas phase, occurring when the vapor pressure of the solid is greater than atmospheric pressure (e.g., iodine, dry ice).

Crystalline solids

Solids composed of particles arranged in a regular, repeating three-dimensional structure.

Amorphous solids

Solids with highly disordered structures and no regular repeating pattern, such as glass and ceramics.

Ionic solids

Solids formed by strong electrostatic attractions in closest-packed arrangements determined by ionic radii; they exhibit low vapor pressures, high melting and boiling points, brittleness, and conduct electricity only when molten or dissolved.

Molecular solids

Solids consisting of distinct individual units of covalently bonded molecules attracted by comparatively weak intermolecular forces, resulting in low melting points and non-conductivity.

Network solids

Substances characterized by strong, directional covalent bonds between nonmetal atoms forming a continuous network with fixed bond angles, yielding high melting points and high hardness.

Graphite structure

A network solid allotrope of carbon consisting of planar layers that are soft because the layers can slide over each other.

Silica ($SiO_2$) structure

A covalent network solid composed of silicon and oxygen atoms bonded in a continuous three-dimensional network.

Diamond structure

A covalent network solid of carbon atoms bonded with fixed bond angles in a rigid, very hard three-dimensional structure.

Metallic solids

Solids characterized by strong, non-directional bonding with free valence electrons that make them malleable, ductile, and thermally and electrically conductive.

Electron sea model

A model of metallic bonding where mobile valence electrons surround a lattice of metal ions, enabling electrical and thermal conductivity.

Group 8A solids

Atomic solids held together solely by London dispersion forces between noble gas atoms, giving them extremely low melting points (such as $0.95\,\text{K}$ for $He$ and $83\,\text{K}$ for $Ar$).