Static Electricity How do electrons interact with each other and with objects around them?

Static Electricity Electric Charge = a form of charge, either positive or negative, that exerts an electric force Three Different Charges: Positive = (+) has more protons than electrons Negative = (-) has more electrons than protons Neutral = equal # of protons (+) and electrons (-)

Static Electricity Objects can become charged when electrons are transferred to or from another object By contact Protons do not move…why? When objects have a charge their electrical make up is imbalanced We call this Static Electricity = an imbalance of electric charge on the surface of an object

+ + + - - - + + - What is the Charge? What charge does this object have? Charge imbalance should always be understood in relative terms 2 neutral objects will neither attract nor rebel each other BUT, if a negatively charged object is brought near a neutral object, the neutral object is now more positive relative to the negative object Therefore they attract + + + - - - + + -

Problem Object A and Object B are both positively charged Object A is much less positive than Object B Therefore will these objects attract or repel one another?

How to Detect Static Electricity Electroscope = an instrument used to detect the presence of electric charges Example = Pith Ball Electroscope An object is brought near to the neutral pith ball If the object is charged = pith is attracted to the object

Law of Electric Charges A charged object has an electric force Electric force = the force exerted by an object with an electric charge creating an: attractive or repulsive force Alike charges rebel Unlike charges attract Electrical Field = the affected space around a charged object The strength of the electric force is related to the amount of charge on each object the distance between the charged objects

Scenario Lightning is an example of static electricity Lightning is a result of very strong negative and positive charges attracting https://www.youtube.com/watch?v=jM8h60S1GsM Do you think it is safe to be in a car during a lightening strike? Why or Why not? It is safe Because, electrostatic charges tend to remain on the surface of objects and are evenly spread out around the object Therefore, the lightning will strike the surface of the car but not effect the people inside the car **all car windows must be shut

Induction When 2 neutral objects are brought close they will neither attract or repel When a charged object is brought near a neutral object it induces the electrons in the neutral object to move This is called Induction Charge Separation A shift in the position of electrons in a neutral object that occurs when a charged object is brought near it *Does not gain or lose electrons!

Application Electrostatics is a branch of science that deals with static charges and static electricity Scientists and engineers study electrostatics in school as they will use it everyday in their field Electrostatic Paint Sprayers Read Text page 470 Use the Ipad to complete the “Research This: Powder Coating” at the bottom of pg. 470

Take-home Assignment In your own words, define static electricity