What is Static Electricity Static Electricity is A

What is Static Electricity?

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

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

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

The Electrostatic Series n n n n Acetate Glass Wool Fur/Hair Ca, Mg, Pb Silk Aluminum Zinc Cotton Paraffin wax Ebonite Plastic C, Ni, Cu Sulfur 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… n n n n Acetate Glass Wool Fur/Hair Ca, Mg, Pb Silk Aluminum Zinc Cotton Paraffin wax Ebonite Plastic C, Ni, Cu Sulfur 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 n Touch something with a charged object n Positively charged object will take some electrons from neutral object, making it positive too n Negatively charged object will give electrons to the neutral object, making it negative too

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

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

How to put static charge on an object 3. By Induction n Bring a charged object near a neutral object without touching it n 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 n Negative rod forces electrons down and makes the leaf negative n Positive rod attracts electrons up and makes the leaf positive n