Solids and the Kinetic Molecular Theory

Dominated by. . .◦ Closely packed

particles◦ Relatively fixed

position◦ Highest

intramolecular attractions

Are. . .◦ Definite shape and

volume◦ Definite melting

point◦ High density ◦ Incompressible◦ Low rate of diffusion

Properties

Structure

Can be crystalline Can be amorphous

Insulin crystals Obsidian

Crystals Have a regular repeating

pattern of particles

Ionic crystals◦ Made of ions – hard and brittle◦ Ex. NaCl

Metallic crystals◦ Made of metals with free moving electrons

Covalent crystals◦ Made of molecules◦ Ex. Quartz (SiO2), water, sugar

Atomic Crystals◦ Made of atoms of one element◦ Ex. Diamond or graphite

Classes of Crystalline Solids

No regular pattern in the particles, without a particular shape

Ex. Glass, plastics, wax, cotton candy

Amorphous Solids