Electrostatics Energy at rest - study of nonmoving electric charge. Static Electricity. Involves Electric charges Forces between them Their behavior in material

Form of Energy Atoms – electrons Energy associated with electrons that move from one place to another.

Electric Charge/Force Charge – gain/loss of e-. Force – when charge particles come near one another. Rule: “Like charges repel, unlike attract”

Electric Fields Region surrounding charged particles. Strength as distance of particle

Charged Particles Ion - a charged atom caused by an imbalance of p+ and e-. positive ions have lost e- negative ions have gained e- The amount of energy required to tear an electron away from an atom varies for different substances.

Triboelectric Series Positive Rabbit’s fur Glass Wool Cat’s fur Silk Felt Cotton Wood Cork Rubber Celluloid Negative Ranks materials according to their tendency to give up their electrons. THE TRIBOELECTRIC SERIES

Law of Conservation Conservation of Charge - electrons are neither gained nor destroyed, but are simply transferred from one material to another.

Coulomb Metric unit for electric charge (C). The symbol for charge is (q). One Coulomb is the charge of 6.24 x 1018 electrons – about the charge going thru a 100 watt light bulb in about 1 second.

Coulomb’s Law For charged particles, the force between the charges varies directly as the product of the charges and inversely as the square of the distance between them. Fel = kq1q2 d2 k = 9.0 x 109 N-m2/C2

Methods of Charging Build up of electric charges. Methods Friction Conduction Induction

Conduction Conductors - materials where the outer electrons are not anchored to the nuclei of a particular atom, but are free to roam. Insulators - materials where the outer electrons are tightly bound to the nuclei and remain with a particular atom, they are not free to roam.

Semi-Conductors Materials which are good insulators in pure crystalline form, but conduction tremendously increases when an impurity has been added. Examples: germanium and silicon. Uses: transistors and diodes.

Superconductors Certain materials (metal alloy and ceramics) that acquire infinite conductivity (zero resistance to the flow of charge) at temperatures near absolute 0. Examples: Mercury, Niobium-Tin, Lanthanum-Barium-Copper Oxide, and Yttrium-Barium-Copper Oxide.

Induction Electrons will move in the conduction surface of an object when a charged object is near it. Excess electrons in the conduction surface will transfer onto another surface. Brings opposite charges

Lightning Electric discharge. Loss of static electricity as electric charges move off an object. Grounding – lightning rod

Electroscope