Liquids and Solids

London Dispersion Force

exists between all molecules

• transient dipole moment elicited by non-uniform distribution of charges

• increase with size

Dipole-dipole

polar molecules interacting

• weak attractive force between two polar molecules with permanent dipoles

• part negative sides of a molecule interacting with partial positive ends of a separate molecule

Hydrogen Bonding

• A strong type of dipole-dipole interaction between a hydrogen atom covalently bonded to F, O, or H

• F-H, O-H, or N-H involved

substances with stronger intermolecular forces..

have higher boiling points

Polar covalent bonds

electrons are shared between atoms with different electronegatitives

Nonpolar covalent bonds

electrons are shared equally between two atoms

Ionic Bonds

Valence electrons are completely transferred from one atom to another

Metallic bonds

bonding between two metal atoms

• form between metal cations and the valence electrons moving freely within the lattice structure

Liquids are…

in ompressible fluids with a definite volume but no fixed shape

Solubility

the degree to which a solute can be dissolved in a liquid (solvent)

Miscibility

The degree to which a liquid mixes with another liquid

Viscosity

the thickness of a liquid

Surface Tension

the ability of a liquid surface to resist external forces

vapor pressure

equilibrium pressure exerted by a vapor above its liquid in a closed system

liquids generally have a lower density than…

solids because the solid molecules are more tightly packed than the liquid molecules

Heterogenous mixture

particles are distributed non-uniformly

homogenous mixture

particles are distributed uniformely

Solids are…

incompressible with a define shape and volume, and have strong intermolecular forces

ionic solids

hard, non-conductive, brittle and high melting point

metallic solids

malleable, ductile, conductive, highly luster, and variable melting points and hardness

Covalent Network Solids

hard, non-conductive, and high melting point

Molecular Solids

Soft, non-conductive, and low melting point

Amorphous Solids

does not have unit cells

Crystalline Solids

crystal patter is defined by a unit cell

Simple cubic

1 atom per unit cell; one atom is at every corner of the cube (1/8 of each atom)

Body-Centered cubic

2 atoms per unit cell; one atom is at the center of the cube while the rest are in the corners (1/8)

Face-centered cubic

4 atoms per unit cell; one atom at the center of all the faces of the cube (1/2 at each face, 1/8 at each corner)