1. Solids
Section 10.3

2. Properties of Solids and the Kinetic-Molecular Theory
Particles of a solid are even closer together than a liquid
Intermolecular forces are much more effective because of proximity
These forces keep the particles in a solid in relatively fixed positions, with only vibrational movement around fixed points

4. Types of Solids Crystalline solids: consist of crystals
Crystal: a substance in which the particles are arranged in an orderly, geometric, repeating pattern
Amorphous solid: the particles are arranged randomly, like glass and plastics

6. Definite Shape and Volume
Solids maintain a definite shape
The volume of a solid changes only slightly with a change in temperature or pressure
The particles are so close together, that it is hard to compress them further

7. Definite Melting Point
Melting: the physical change of a solid to a liquid by the addition of energy, usually as heat
Melting point: the temperature at which a solid becomes a liquid
A solid melts because the kinetic energies of the particles increase and overcome the attractive forces holding them together

8. Density Generally substances are most dense in the solid state
Solids are slightly denser than liquids and much denser than gases
This is because the particles are more closely packed

9. Compressibility Solids are generally less compressible than liquids
Can be thought of as incompressible

10. Diffusion Solids have an extremely low rate of diffusion
It is millions of times slower in solids than in liquids

11. Crystalline Solids
Crystal structure: 3-D arrangement of particles of a crystal
Lattice: the coordinate system that represents a crystal structure
The crystal will have one of seven types of symmetry

12. Seven types of crystalline systems