What is Static Electricity?

Everything we see is made up of tiny little parts called atoms. The atoms are made of even smaller parts. These are called protons, electrons and neutrons. They are very different from each other in many ways. One way they are different is their "charge." Protons have a positive (+) charge. Electrons have a negative (-) charge. Neutrons have no charge. Usually, atoms have the same number of electrons and protons. Then the atom has no charge, it is "neutral." But if you rub things together, electrons can move from one atom to another. Some atoms get extra electrons. They have a negative charge. Other atoms lose electrons. They have a positive charge. When charges are separated like this, it is called static electricity.

If two things have different charges, they attract, or pull towards each other. If two things have the same charge, they repel, or push away from each other.

So, why does your hair stand up after you take your hat off? When you pull your hat off, it rubs against your hair. Electrons move from your hair to the hat. Now each of the hairs has the same positive charge. Things with the same charge repel each other. So the hairs try to move away from each other. The farthest they can get is to stand up and away from all the other hairs.

If you walk across a carpet, electrons move from the rug to you. Now you have extra electrons. Touch a door knob and ZAP! The electrons move from you to the knob. You get a shock.

Static electricityStatic electricity is a buildup of charge on an object.

Static ElectricityLike charges repel – unlike charges attract

Positive (+) and Negative (-) charges attract or pull.

Positive (+) and Positive (+) charges repel or push.

Negative (-) and Negative (-) charges repel or push.

http://amasci.com/emotor/vdgdemo.html Some atoms hold on to their electrons more tightly than others do. Positive items in the series are at the top, and negative items are at

the bottom: Human hands (usually too moist, though) Very positive Rabbit Fur Glass Human hair Nylon Wool Fur Lead Silk Aluminum Paper Cotton Steel Neutral Wood Amber Hard rubber Nickel, Copper Brass, Silver Gold, Platinum Polyester Styrene (Styrofoam) Saran Wrap Polyurethane Polyethylene (like Scotch Tape) Polypropylene Vinyl (PVC) Silicon Teflon Very negative

When the motor is turned on, the lower roller (charger) begins turning the belt. Since the belt is made of rubber and the lower roller is covered in silicon tape, the lower roller begins to build a negative charge and the belt builds a positive charge. You can understand why this charge imbalance occurs by looking at the triboelectric series: Silicon is more negative than rubber; therefore, the lower roller is capturing electrons from the belt as it passes over the roller.

Do Now:What do all magnets have in common?

1. With your elbow buddy, use the bar magnet and the horseshoe magnet. Take turns with others at your table.

2. See if you can make a paper clip stick to different parts of each magnet.

3. Draw a diagram in your journal showing the number and location of paper clips on each magnet.

MagnetismMagnets have 2 poles, North and South

Opposite poles (North and South) attract

Like poles (South and South) (North and North) repel

The area around a magnet where the force is strongest is called the magnetic field.

Electricity• Electricity is a flow of electrons

•An electric circuit is a pathway that allows the flow of electrons.

•An electric circuit has 3 parts:

1. Power/Energy source

2. Switch

3. Resistor - Objects that require an electrical current to work (ex. light bulbs, fan, bell).

Open and Closed Circuits

• An open circuit does not allow the flow of electricity (lights turned off)

• A closed circuit allows the flow of electricity (lights turned on).

1. Draw an open circuit with 6 resistors.

2. Draw a closed circuit with 4 resistors and 2 power sources.

3. Draw a closed circuit with 5 resistors.

2 Types of Circuits

Series circuits (Christmas lights) are all wired together to the power source. If one bulb goes out, they all go out.

Parallel circuits (store signs) are wired separately to the power source. If one bulb goes out, the others stay on.

Conductors Metals are good conductors of

electricity (wires) They CONDUCT electricity

Plastic is a poor conductor, or insulator, of electricity (cover the wires).

INSULATORS do not conduct electricity

BBC website http://www.bbc.co.uk/schools/scienceclips/ages/8_9/circuits_conductors_whatnext.shtml