Electricity

Atoms
protons, neutrons, electrons, nucleus, electron cloud
ions, normal state, positive ion, negative ion

Electrostatics
conservation of charge, like charges repel, unlike charges attract
Coulomb’s Law, force between two charged particles depends on relative charges and inversely related to square of distance
k = 9 x 109 Nm²/C² (huge number)
similar to gravity but gravity is very weak force on mostly large masses while electrical force is very strong but acting on weak charges, may attract or repel

Current
current is speed or rate of electron flow = ampere, difference in charge along a connected system leads to Potential Energy, electrons flow through the wire because of a voltage across the wire
resistance, material (insulator, conductor, semi-conductor), length, diameter, temperature, ohm = unit of resistance, Ohm’s Law

circuit types:
series (more devices increase resistance), everything hooked up in a row, current is constant (all electrons flow through all devices), total resistance is the sum of individual resistances, voltage drop across each device is proportional to its resistance
parallel (more devices reduces resistance), each loop is like own circuit, voltage is constant (all go from same high to low), current varies (inversely proportional to resistance), total current is sum of individual loop currents, can lead to overloading by allowing too much current to flow.

What are the components of an atom? How are they arranged? What makes ions different?

Write and explain Coulomb’s law. How is it similar to Newton’s law of gravitational attraction? How is it different?

What is an electrical current and what makes it flow? Write Ohm’s law and explain how it describes the factors which affect a current’s strength.

Sketch examples of series and parallel circuits (2 separate sketches). Contrast the effects on current, voltage, intensity of lights, and longevity of the battery. Explain which system is most likely to become overloaded?

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