1. Conductors and Insulators

2. Conductors – Materials through which electrons flow easily. (Valence Electrons are removed easily, allowing many free electrons) Good Conductors – Silver, Copper, Aluminum, Gold, Platinum Most Metals will conduct

3. Do you think that this is just luck? Some Gases conduct – Neon, Argon, Mercury Vapor, Sodium Vapor

4. Electron Flow is from Negative to Positive Electrical Impulse – 186,000 miles/sec A circuit wrapped around the earth 7 times would take about 1 sec to light. Individual Electrons don’t move that far but the impulse does.

5. Insulators – Materials through which electrons do not flow easily. Very Few Free Electrons Plastics, Rubber, Wood, Glass

6. Resistance – Less pure conductors make the passage of electrons difficult. The opposition to the flow is resistance. Factors that determine resistance 1.Kind of metal 2.Temperature 3.Length 4.Cross sectional area The Basic unit of Resistance is the Ohm  The formula symbol is R

7. Relative resistance of different materials Copper 1 Aluminum 1.7 Iron5.65 Silver.94 Tin7.7 Brass3.57 The lower the number the easier the electrons can flow.