Static Electricity: electrons building up somewhere

Atomic Structure: Atoms have positively charged nuclei (relatively massive), surrounded by negatively charged electrons (much less massive).
 

Some materials tend to gain or lose electrons; this accumulation of charge is known as "static electricity."

• Charging the rubber rod by rubbing it with nylon.

Like charges repel, unlike charges attract.

• Charging the Electroscope by touching with a charged object (Click here for animation showing this process.)

Charges can act over a distance.

• Electrostatic induction:  bringing a charged object near, but not touching, the electroscope.
• Pulling the can

• Pulling the ping pong ball
• Comb bending water

• Balloon on ceiling

Static Electricity in everyday life
Hair
Shocking Hands
Lightning
 
 
 

Current Electricity: flowing electrons

Battery:  acts like an "electron pump" producing current electricity.

Conductor:  a material through which electricity can flow easily. What are some examples?

Insulator: a material through which electricity doesn't flow easily. What are some examples?

Closed circuit:  a continuous path of conductor so that electricity can flow from one end of the battery (or one pole of the generator), through the device (light bulb) and to the other end of the battery (or other pole of the generator).

• Incandescent light bulb:  electrons get "backed up" in the filament, bang into one another, causing it to get hot and glow.

 

 
 
 
 
 
 
 
 
 

Note: You should feel comfortable drawing and explaining this!  Check out the Batteries and Bulbs Lab if you are confused.
 

• Fluorescent bulb: a gas in the tube is excited by an electric field, causing it to glow.

Open circuit:  a circuit with a break in it.

• Switch: opens and closes the circuit
• Salt water switch

Short circuit: a circuit that by-passes the device (light bulb), that is, one where the electricity can flow from one end of the battery (or generator) to the other without going through the device.  When this happens, so much current flows through the circuit that it quickly overheats and can cause a fire.  Can you draw a picture of a short circuit?

• Fuses and circuit breakers: open the circuit if too much current is flowing.  This reduces the threat of fire.