Static Electricity

2 Laws of Static Charges

Law of attraction = particles with opposite charges attract each other

Law of repulsion = particles with “like charges” (same charges) repel each other

Electrical Discharge

• When an object is charged, it stays that way until the electrons have a path to escape

• When charges are transferred VERY quickly this is called ELECTRICAL DISCHARGE

• Sparks are an example of this• Lightning is an a VERY large electrical discharge• The air becomes a passage for electrons to

travel and causes a spark

What makes the light and Crackling Sound during a spark?

- Collisions between air particles and moving electrons!

- when your negatively charged hand

reaches for the neutral doorknob, the excess electrons transfer

due to induction

GROUNDING

• Removing excess charge on an object through electron transfer

• Connecting a charged object to the Earth’s surface- When you connect a chargedobject to the ground = apath for charges to travelto and from the ground

Electrical Insulators and Conductors

Insulators: resists or blocks movement of electronsEx: wood, rubber, plastic

Conductors: allows movement of electrons through Ex: copper and aluminum

Electrostatic Series

Triboelectric Series

Electron Affinity

- The tendency of a substance to hold onto electrons

Using the Electrostatic series, how can we determine which charge will the following substances get after they have been rubbed together?

Ebonite Rod and Fur

Glass and Silk

HOW CAN OBJECTS BECOME CHARGED?

CHARGING BY FRICTION

CHARGING BY FRICTION

• two objects rub together, the force removes electrons from one object and transfers them to the other object

• Object that lost electrons = positively charged

• Object that gained electrons = negatively charged

CHARGING BY CONTACT

CHARGING BY INDUCTION

Grounding the Object Using a Water Tap or your Finger

References

• A Dercho• Investigating Science 9 -Pearson