STATIC ELECTRICITY How do electrons interact with each

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=j. M 8 h 60 S 1 Gs. M � 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

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