What is Static Electricity?

Static Electricity is… A stationary build-up of electric charge (electrons) on a material A stationary build-up of electric charge (electrons) on a material Electricity that does not move (static vs. dynamic) Electricity that does not move (static vs. dynamic) Shocking! Shocking!

Types of Charges Most objects are neutral – electrically uncharged Most objects are neutral – electrically uncharged If 2 neutral objects are rubbed together, one becomes positively charged (loses electrons) and the other becomes negatively charged (gains electrons) If 2 neutral objects are rubbed together, one becomes positively charged (loses electrons) and the other becomes negatively charged (gains electrons) Direction of electron flow called the “ELECTROSTATIC SERIES” Direction of electron flow called the “ELECTROSTATIC SERIES”

The Electrostatic Series Acetate Acetate Glass Glass Wool Wool Fur/Hair Fur/Hair Ca, Mg, Pb Ca, Mg, Pb Silk Silk Aluminum Aluminum Zinc Zinc Cotton Cotton Paraffin wax Paraffin wax Ebonite Ebonite Plastic Plastic C, Ni, Cu C, Ni, Cu Sulfur Sulfur Gold, Platinum Gold, Platinum Weak hold on electrons Strong hold on electrons

The Electrostatic Series Acetate Acetate Glass Glass Wool Wool Fur/Hair Fur/Hair Ca, Mg, Pb Ca, Mg, Pb Silk Silk Aluminum Aluminum Zinc Zinc Cotton Cotton Paraffin wax Paraffin wax Ebonite Ebonite Plastic Plastic C, Ni, Cu C, Ni, Cu Sulfur Sulfur Gold, Platinum Gold, Platinum For example: A plastic comb is rubbed with wool The wool gives up electrons (weaker hold); becomes positively charged The plastic comb takes electrons and becomes negatively charged

Let’s try another one… Acetate Acetate Glass Glass Wool Wool Fur/Hair Fur/Hair Ca, Mg, Pb Ca, Mg, Pb Silk Silk Aluminum Aluminum Zinc Zinc Cotton Cotton Paraffin wax Paraffin wax Ebonite Ebonite Plastic Plastic C, Ni, Cu C, Ni, Cu Sulfur Sulfur Gold, Platinum Gold, Platinum Your cotton sweater rubs against your silk shirt… Negative charge: Cotton (gained electrons) Positive charge: Silk (lost electrons)

How to put static charge on an object 1. By Contact Touch something with a charged object Touch something with a charged object Positively charged object will take some electrons from neutral object, making it positive too Positively charged object will take some electrons from neutral object, making it positive too Negatively charged object will give electrons to the neutral object, making it negative too Negatively charged object will give electrons to the neutral object, making it negative too

Charging by Contact 1. Friction Between any two materials Between any two materials Rubbing it with something Rubbing it with something

Charging by Contact 2. Conduction When 2 objects with different amounts of charge come into contact When 2 objects with different amounts of charge come into contact Electrons move from one object to the other Electrons move from one object to the other

How to put static charge on an object 3. By Induction Bring a charged object near a neutral object without touching it Bring a charged object near a neutral object without touching it Let’s check out the electroscope! Let’s check out the electroscope!

Charging by Induction Bringing a charged rod near the electroscope will INDUCE the same charge on the silver leaf Bringing a charged rod near the electroscope will INDUCE the same charge on the silver leaf Negative rod forces electrons down and makes the leaf negative Negative rod forces electrons down and makes the leaf negative Positive rod attracts electrons up and makes the leaf positive Positive rod attracts electrons up and makes the leaf positive