• Connect the potato clock and explain how it works. 
• The chemical reactions in the battery causes a build up of electrons at the anode (base of the battery or zinc metal strip inserted into the battery ) and positive charges at the cathode (top of the battery or copper strip inserted into the battery) This results in an electrical difference between the anode and the cathode.  
• If you link the anode and the cathode with copper wire, you get a flow of electrons.

• The electrons want to rearrange themselves to get rid of this difference so they  repel each other and try to go to a place with fewer electrons...this provides the electromotive force that gives the flow of electrons necessary to power the clock.

• Use the solar battery and the overhead and use it to create a circuit with a buzzer.
• Add a switch to the circuit and control the buzzer with a switch.
• Explain how the solar cell works - go to CIRCUITS for an explanation.
• The dark blue silicon is treated so when sunlight strikes the solar cell, electrons are knocked loose and move to the dark blue treated surface...if you join the two parts with a copper wire, you get a flow of electrons.

• Create a circuit and connect a battery to a light bulb. (try two light bulbs)
• Create a switch at the point in the circuit where you see the arrow and control the light bulb with the switch.

• Create a circuit and connect a battery to a buzzer.
• Control the buzzer with a switch.
• Attach a buzzer and a light bulb and control with a switch.

• Connect the class electromagnet.
• Explain how it works. LINK
• An electric current flowing through a wire produces a magnetic field.  Coiling the wire around an iron core increases the effect and the power of the electromagnet.

• Use a large magnet and iron filings to represent the force fields around a magnet that provide the electromotive force to get electrons moving in copper wire.
• Our iron filings are encased in a plastic container so you can use the magnet to make "iron filing icicles."

• Connect the class motor and explain how it works.
• The armature (or rotor - the rotating bar) is an electromagnet, while the field magnet is a permanent magnet.
• Opposites attract and likes repel. So if you have two bar magnets with their ends marked "north" and "south," then the north end of one magnet will attract the south end of the other. On the other hand, the north end of one magnet will repel the north end of the other (and similarly, south will repel south).
• This creates the rotary motion.

• Use the class generator and explain how it works.
• The basic idea behind a generator  is to convert mechanical energy into electricity by rotating coils of wire in a strong magnetic field.
• A generator is just like a motor except water or wind or steam or a human push turns the armature which in turn creates electricity rather than the electricity turning the armature.
• A loop of wire spinning through a magnetic field will create an alternating current. Note: current will flow only if the circuit connected to the generator is complete...also note that the current keeps changing direction - that's what makes an alternating current.

• Connect a battery and 2 bulbs using a series circuit .
• Add a switch on the left side to control the lighting of the bulbs.
• There is only one path for the electrons to take.

• Connect a battery and 2 bulbs using a parallel circuit.
• Add a switch on the left to control the lighting of the bulbs.
• There is more than one path for the electrons to take.

• Demonstrate the galvanometer and explain how it works.
• A galvanometer is an instrument used to determine the presence, direction, and strength of an electric current in a conductor - basically a magnetic needle is deflected by the presence of an electric current in a nearby conductor. 

• Connect the ammeter to a small battery.  The ammeter is  an instrument used to measure and indicate the rate of flow of an electric current, usually in amperes.
• An amp is a measuring unit of the intensity of an electrical current crossing a given point of a conductor in one second.

• Create an electric current with a hand battery.
• Place your hands on each plate.  If you can't get a microammeter, connect the alligator clips to a set of earphones. (the static you hear is electric current)
• You can also duplicate this experiment using a holiday light with 5 cm. ends, a zinc screw, a copper screw and a lemon.  

• Look inside the battery that we've sliced open and explain how it works.
• A chemical reaction within the pasty mixture strips electrons from some of its atoms. These excess electrons collect on the zinc can, which acts as the negative terminal.
• At the carbon rod are atoms with a shortage of electrons.
• The electrons at the negative terminal want to go to positive terminal, they just need a way to get there. In our light bulb circuit, the way to get there is through the wire.

Mechanisms Using Electricity

AC/DC  Exploratorium  Grade 5 Science  Hunkin's Experiments

• In this section you are asked to create a mechanism which uses electricity.  You can make anything from a small car to a burglar alarm or an electronic matching quiz or a crane which uses an electromagnet.
• Lego is a great way to go...film canister lids make great wheels.
• Here's a few sample projects: telegraph key, electromagnet crane, burglar alarm, buzzer puzzle, car, boat, etc.