1. How do charges flow through the components of a circuit?
Electrical Circuits
How do charges flow through the components of a circuit?
Recall static electricity is a build up of charge until discharge like a spark jumping from hand to metal doorknob or lightning. Current electricity is electic charges flowing ina circuit througha conductors in a controlled way.
Static electricity involves charges that build up and stay in the same place on a an object. How could you store the charges to use later?

2. Vocabulary
Current electricity, joule, electric cell, battery, load, circuit, ampere, electron flow, direct current, alternating current, series and parallel circuits, electric potential difference, voltage, volt, voltmeter, cells, resistor, ohm, Ohm’s law,

3. What is current electricity?
An electric current is a flow of electric charge through a conductor
In electric circuits this charge is carried by moving electrons in a wire.
It can also be carried by ions in an electrolyte, or by both ions and electrons such as in an ionised gas (plasma).
Malcolm and Angus Young developed the idea for the band's name after their sister, Margaret Young, saw the initials "AC/DC" on a sewing machine. "AC/DC" is an abbreviation meaning "alternating current/direct current" electricity.
As slang for "bisexual," c.1940; the notion is of working both ways. 

4. Parts of an Electric Circuit
(Energy) source – battery or wall outlet, energy measured in joules (J)
Conductor – wire to conduct electrons
Load – device that converts electrical energy into other forms of energy such as light or sound. Eg. Lightbulbs, speakers, heaters, motors.
Switch – a device for making and breaking the connection in an electric circuit (controls flow of electrons).
Complete circuit: electrons flow freely whole circuit
Incomplete circuit: no electrons flow due to break in circuit (switch is off)

5. Energy Sources in Circuits

6. Cells and batteries

7. Intro to Current Electricity, 5min

8. Electrical Cells and Batteries
An Electrochemical cell is a device that converts chemical energy into electrical energy.
A battery is a collection of cells

9. Electrochemical Cell All cells contain 3 parts: a
positive electrode (cathode),
negative electrode (anode) in
An electrolyte (chemical medium)

10. How Does a Cell Work?
Chemical reactions in the battery causes a build up of electrons at the anode (negative terminal).
This results in an electrical difference between the anode and the cathode. unstable build-up of the electrons.
The electrons repel each other and try to go to a place with fewer electrons (toward the cathode).
The electrons can’t flow through the electrolyte.
At the same time, electrons move away from the cathode, leaving it positive.

11. How Batteries Work
When the circuit is closed (a wire connects the cathode and the anode), the electrons go through the wire, lighting the light bulb along the way.

12. How does a battery provide energy?
Batteries “push” electrons through conductors (wires) when connected to a circuit.
Energy to “push” electrons is created by separating positive and negative charges. 
Energy is the ability to do work (to make things move or change).
A flashlight battery has two terminals called electrodes in a moist paste called an electrolyte that conducts electricity.
Electrons build up at one terminal, making it negatively charged.
At the same time, electrons withdraw from the other terminal ,leaving it positively charges. Once the charge are separated, the charges have the ability to do work on something , such as lighting a bulb

13. How does a cell work?
Because opposite charges attract each other, it takes energy to separate positive and negative charges. 
In a cell, chemical reactions separate the positive and negative charges. The chemical energy does the work.
A battery  “stores” energy  so that it can be used  later  to do work.  We say that a battery is a source of electric potential energy – stored energy that has the potential to make something move or change. 
Friction provides energy

14. What happens when you recharge a cell?
When you recharge a battery, you change the direction of the flow of electrons using another power source, such as solar panels. 
The electrochemical processes happen in reverse, and the anode and cathode are restored to their original state and can again provide full power.

15. How batteries work Ted Ed video

16. Two types of Cells
There are two types of cells: Primary and Secondary

17. Primary Cell (Dry Cell)
Dry cell contains a moist paste as an electrolyte. 
Primary cell cannot be recharged because chemical reaction is irreversible. 

18. Secondary Cells (Wet Cell)
In a wet cell the electrodes sit in a liquid solution. 
Consists of an electrolyte solution, a zinc rod, and a copper rod, conductor, and a salt bridge. 

19. Secondary Cells (Wet Cell)
Secondary cell can be recharged using electrical energy to reverse the chemical reaction
Eg. Lead storage batteries (car battery) and nickel – cadmium storage cell

20. How to make a Lemon Battery

21. Lemon Battery Explained: Sci Show

22. How to make a battery with spare change

23. Circuit Symbols
Cell: 2 parallel lines, shorter line is the negative terminal
Some circucuits require >1 cell.

24. Simple Circuit Diagram
electrons flow out of the negative terminal, through the circuit and into the positive terminal of the source
Posiitve is the long side

25. Types of Circuits
Circuits or devices within circuits, can be connected in series or parallel.

26. Circuits in Series
Components are connected one after another in a single loop
Current must flow through all devices
Current is the same at all points
Voltage is shared between components
If you add electric loads, each on get less electric pressure (light bulbs will dim as more are added)
We use series circuits in:
                Computers, radios, TV’s, rockets

28. Circuit in Series

29. Draw example of Series Circuit

30. Series

32. Circuit Diagram
When switch is closed, electrons will flow and the light turns on. In this diagram, e flow counterclockwise direction from negative terminal though bulb, to positive terminal.

34. Parallel Circuits
Have two or more paths for electrons (current) to flow
Current is shared between the branches (splits up) 
Only some of the current goes through each device. 
Sum of the current in each branch = total current
Voltage loss is the same across all components
If circuit is broken, the current may pass through other pathways and other devices continue to work
None of the current goes through more than one device. 

35. Circuit in Parallel

36. Which circuits are in series and which are in parallel?

38. Homework
CYU p 305
#1, 2, 4, 5, 6, 7, 8, 9, (10, 11, 13, 14, 15)
Make a battery out of pennies, cardboard, tin foil, vinegar, wire, light