2.  Electricity is caused by the flow (or net movement) of Electrons  Electric Current – the rate that positive charges flow in a circuit › Actually a measure of the rate that negatively charged electrons move  Electrons Will Move From Higher To Lower Potential

3.  Measured in Amperes (A) › Ampere = 1 Coulomb of charge per second  Voltage or Potential Difference – measure of potential energy (in Joules) › Voltage occurs across the two terminals of a battery and range from 1.5 V for a small battery to 12 V for a car battery › Voltage sets charge in motion  Electrons move from the negative terminal to the positive terminal

4.  Resistors oppose the rate of charge flow in the circuit  Caused by internal friction  The resistance of the filament of a light bulb determines how bright the bulb is › Example: 4o Watt bulb has a higher resistance than a 100 Watt bulb › Resistance = Voltage / Current  Unit - Ohms

5.  Conductors – allow electrons to flow easily › Contain a lot of free electrons › Offer Little Resistance To Current Flow › Good Conductors  Metals (copper, gold, silver, aluminum)  Electrolyte Solutions  Insulators – do not allow electrons to flow easily or at all › Contain Few Free Electrons › Insulator Materials  Air, Wood, Glass

6.  As Current Increases – Potential Difference (Volts) Increase  As Current Increases – Resistance Decreases

7.  Circuit – bulb, battery, and wires › Closed Circuit – completed path – electricity flows › Open Circuit – not a complete path – no current › Parallel Circuit – multiple path for a circuit › Series Circuit – one path for a circuit