1. States of Matter: Solids Physical Science Chapter 5.2

2. Solids  Thermal energy cannot overcome intermolecular forces of attraction  Physical properties of solids:  Density  Strength - maintain shape under force (Brittleness)  Elasticity - stretch and return to same shape  Ductility - bend without breaking (form wire)  Thermal conductivity - transmit heat energy  Electrical conductivity - allow electricity to flow

3. Crystalline Solids  Crystalline solids have molecules arranged in orderly, repeating patterns  Amorphous solids have molecules arranged any which way  Salt, water, metals, most naturally occurring solids

4. Polymers  Polymers are made of long chains of repeating molecules  Plastics are amorphous solid polymers  Melting point above room temp, but less than metals  Good strength and elasticity

5. Heat Conduction and Solids  Heat conduction is the transfer of heat by direct contact.  Hand, spoon, cocoa  Transfer of energy  Thermal equilibrium occurs when two bodies have the same temperature.

6. Thermal Conductors and Insulators  Solids conduct heat best because molecules are close together  Good electrical conductors are usually good thermal conductors  Insulators are poor conductors of heat  Heat does not travel through a vacuum