1. Electricity Electricity

2. Polarity NSNSNSNS LIKES REPEL! NSNS OPPOSITES ATTRACT! SAME RESULT WHEN DEALING WITH ELECTRICAL CHARGES

3. - Cathode Ray Tube Experiment Firing charged particles Vacuum tube filled with inert gas (does not react!) inert gasinert gas +

4. What did this prove? ► What is the charge of the particle?  Negative  Opposites attract! ► What is the mass of the particle?  Had a smaller mass than a hydrogen atom  Concluded that it is one of the particles that make up an atom!  The tiny, negative ELECTRON was discovered!

5. Charges in Objects ► Under normal circumstances, substances have a neutral charge ► But charges have the ability to move around creating a charge differential Electric potential- voltage

6. Electric Potential ► Electrons can be moved “UP” to give them potential – voltage. ► This requires energy. ► They can then be allowed to come “down” using the energy stored in them. Energy put in! Energy released! Energy stored!

7. Generator: voltage and current Gas powered turbine that “pushes” electrons. This pressure is called the voltage; measured in volts. The number of electrons in motion per second is called the current; measured in amperes (amps). 1 amp physically means that 6.24 E18 electrons move through a wire every second

8. Voltage, Current and Electricity used ► If you live in the United States, the power outlets in the wall of your house or apartment deliver 120 volts each. United StatesUnited States ► electricity consumed (measured in watts) = amps x volts  Energy = # electrons x how fast they are being “pushed” ► Example: space heater. You measure the amount of current flowing from the wall outlet to the heater, and it comes out to 10 amps. How many watts does the heater use? ? volts 120 v 10 amps x 1200 watts

9. Light Bulbs! ► Watts = amps x volts: This holds true for any electrical appliance. ► If you plug in a light and it draws half an amp, it's a __________ light bulb. 60 watt! ? 0.5 amps = x120v

10. Light Bulbs #2 If you plug in a 30 watt light bulb and it draws 0.25 amps, how many volts is the outlet? If you plug in a 30 watt light bulb and it draws 0.25 amps, how many volts is the outlet? 30 watt! 30 watt 0.25 amps = x ? v 120 v

11. Circuits ► The source of electricity must have:  A positive terminal  A negative terminal ► The source will want to push electrons out of its negative terminal at a certain voltage.  Ex: one AA battery wants to push electrons out at 1.5 volts. ► The electrons flow from the negative terminal positive terminal through a conductor (copper wire).

12. Electric Circuits Circuit not closed No battery! Circuit complete

13. Series Circuits + - Path of electrons +++ + -- - -

14. Parallel Circuits + - Path of electrons + + -- + -

15. ► Battery: power source ► Switch: Opens/closes circuit ► Light ► Motor ► Capacitor: Stores electricity ► Fuse: Safety: ”blows” with electrical surge ► Resistor: Restricts flow of electricity Circuit symbols M - +

16. Smallest and lightest! Nobel Gases!

17. - Cathode Ray Tube Experiment Firing charged particles Vacuum tube filled with inert gas (does not react!) inert gasinert gas +