REVIEW Which part of the atom stores negative charges? ELECTRONS

Define electricity Static Electricity Notes Charge Quick Activity

The Atom Proton: positive Neutron: neutral Electron: negative Electron Cloud Nucleus

How does an object become charged? When an object is NEUTRAL it is covered with equal numbers of protons and electrons When an object becomes CHARGED it has either lost or gained electrons

Negatively Charged An object becomes negatively charged when it gains electrons.

Positive Charge On object will become positively charged when it loses electrons

Charged Object Interact Likes Repel! Opposites Attract!

3 Basic Concepts 1.There are 2 kinds of electrical charges, positive and negative. 2.Objects become charged when they either lose or gain electrons. 3.Like charges repel and opposite charges attract.

Charge Activity 1.Blow up the balloon. 2.Pour a few squares of paper out on your tabletop. 3.Hold the balloon over the squares and observe what happens. 4.Now rub the balloon on your sweater or in your hair. 5.Hold the balloon again over the squares and observe what happens. 6.Answer the questions on the next slide.

Charge Activity 1.What are the charges of the balloon and squares of paper before rubbing? 2.What is the charge of the balloon after you rubbed it? How did it acquire this charge? 3.Why do the squares of paper jump up and down between the balloon and tabletop?

Review Question: Which part of the atom stores negative charges? ELECTRONS Question: How do objects become charged? Gain electrons  negative Lose electrons  positive

REVIEW Question: What is the result of gaining electrons? losing electrons? GAIN  NEGATIVE CHARGE LOSE  POSITIVE CHARGE Question: Name the three methods of charging

Methods of charging notes

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18 Conductors & Insulators Conductors—electrons move easily Conductors—electrons move easily Ex: metals, water, people Ex: metals, water, people Insulators—electrons do not move easily Insulators—electrons do not move easily Ex: plastic, rubber, glass Ex: plastic, rubber, glass

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21 Methods of Charging Friction Friction Electrons are transferred when materials RUB against one another Contact (or Conduction) Contact (or Conduction) Electrons are transferred from one material to another by simply TOUCHING

Contact (or Conduction) Contact (or Conduction) Electrons are transferred from one material to another by simply TOUCHING 22

23 Induction Induction Charges are separated by bringing one material NEAR another (without direct contact)

24 Induction

25 Polarization Polarization Charging an insulator; positives and negatives rearrange within the atoms.

26 Charging by induction occurs during thunderstorms polarizes the environment. How do you get rid o the excess charge? ______ _ _ _ _ _ ______ _

27 Grounding Removing charge off a conductor by touching it Removing charge off a conductor by touching it

28 Lightning is grounding

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REVIEW QUESTION: What is the result of gaining electrons? losing electrons? GAIN  NEGATIVE CHARGE LOSE  POSITIVE CHARGE Question: Name the three methods of charging Conduction Induction Friction

REVIEW QUESTION: Janae slides across the carpet in her socks and reaches out to touch the door knob. As her hand reaches out towards the door knob she is shocked. This is an example of charging through ____ and release of charge through ____. FRICTION GROUNDING Question: Clouds release their excess negative charge trough lightning. Lightning is an example of ___. Grounding

Review Question: Classify the following types of charging Direct Contact Rubbing Close Proximity Question: One bulb in Jael’s string of Christmas lights is blown, but the others are still glowing because Conduction Friction Induction

Electricity Basics

Current Flow of charge Flow of charge Symbol: I Symbol: I Unit: Ampere (A) Unit: Ampere (A) 1 A = 6.24 billion electrons per second! 1 A = 6.24 billion electrons per second!

Potential Difference The “push” that moves a charge along a conductor The “push” that moves a charge along a conductor Also known as voltage Also known as voltage Symbol: V Symbol: V Unit: volts (V) Unit: volts (V) Voltage source—battery Voltage source—battery

Resistance Opposition to the flow of charge Opposition to the flow of charge Symbol: R Symbol: R Unit: Ohm (  ) Unit: Ohm (  ) Resistance depends on: Resistance depends on: Conductivity of material Conductivity of material Thickness Thickness Length Length Temperature Temperature

Ohm’s Law V = IR

Practice A 12 volt battery produces 0.30 A of current in a piece of copper wire. What is the resistance of the wire? V = 12 V I = 0.30 A R = ? R = V = 12 V I 0.30 A R = 40 

AC/DC AC—alternating current DC—direct current

Parts of a Circuit Conducting path (wires) A load (lightbulb, appliance, resistor) Voltage source (battery)

For a circuit to work it must be (a complete, uninterrupted path)

A switch can be used to open and close a circuit, but one is not necessary for a circuit to work.

Series Circuits One path = 1 current If one part goes out, all parts go out Voltage is divided among parts Resistance increases as more parts are added

Parallel Circuits Multiple paths=multiple currents Voltage is same across each path; not shared If one part goes out, the others stay on Resistance decreases as more parts are added

Example of a Series within Parallel A and B are in series with each other, but are in parallel with C A and B share voltage If the battery is 6 volts, then C gets 6 volts but A and B get 3 volts apiece

Review Question: Classify the following types of charging Direct Contact Rubbing Close Proximity Essential Question: One bulb in Jael’s string of Christmas lights is blown, but the others are still glowing because the lights are in parallel circuit Conduction Friction Induction

Review Question: The battery for the following circuit has a potential difference of 12 volts. How much voltage is flowing through each bulb? Question: Classify the following type of circuit parallel circuit A, B, & C:4 volts each D & E: 6 volts each F:12 volts ABCABC DEDE F

Review Question: As Patsy walks near the Van de Graff machine her hair begins to stand on end. What type of charging is she experiencing? Induction Question: Classify the following type of circuit series circuit

Thursday, December 5, 2013 Bell Ringer: Draw a circuit with one battery and 4 bulbs in which two of the bulbs are connected in series and the overall connection is parallel. Essential Question: Which bulb will shine the brightest in the following circuit? Bulb F is the brightest because it has the most voltage Electricity Test Today ABC DE F

Electricity Test V = I R Voltage = (current)(resistance) After the test:  Complete Magnetism Vocabulary