CHAPTER 16 Electric Charge and Electric Field In static electricity, electrons are transferred to an object and it is – while the other object becomes + Opposites attract…like charges repel. The law of conservation of electric charge states that the net electric charge produced in any process is zero.

16-2 Electric Charge in the Atom Atoms have electrons in an orbit or cloud. When electrons are gained, an atom becomes - …when electrons are lost, - a- makes a +. Molecules with two different charged ‘ends’ are polar molecules. Subtract electronegativities and greater than.4 = polar bond…two ends = a polar molecule.

16-3 Insulators and Conductors Conductors carry a charge easily. Insulators are nonconductors. Semiconductors are borderline or act like both conductor and insulator at different times. Free electrons are required for a substance to be a good conductor.

16-4 Induced Charge; the Electrosope See diagram p479 for charge by contact and by induction. An electroscope is a device used to measure or detect a charge. Electrometers are an electronic device that measures a charge.

16-5 Coulomb’s Law F=k (Q 1 Q 2 )/r 2 Charles Coulomb ( ) The Coulomb is the SI unit of charge. k= 8.988x109(N. m 2 )/r 2 One electron = 1.602x C F=[1/(4pe o )] (Q 1 Q 2 )/r 2 e o =1/4 p k= 8.85x C 2 /N. m 2 See Example 16-1 p483

HOMEWORK P497 q1 and pr#1-8