<p>SNC1D Name: ______Date: ______</p><p>Unit 3 - Physics (The Characteristics of Electricity)</p><p>Electricity is a form of energy produced from a variety of sources. Think about all of the things that you do in a typical day...and think of how many of those things require electricity.</p><p>In this unit we will be studying... 1. ...static electricity [Chapter 11] 2. ...how electricity is generated and used and its effects on the environment [Chapter 12] 3. ...electrical currents and how they can be controlled and used. [Chapter 13]</p><p>Chapter 11 - Static Electricity</p><p>11.1 - What is Static Electricity?</p><p>Remember the structure of the atom from Chapter 6 in the Chemistry unit: -______(positive charge) & ______(no charge) are in the nucleus and do not move from one atom to another -______(negative charge) move in the space surrounding the nucleus, and can move from one atom to another</p><p>Objects are neutral when the number of protons = the number of electrons -if there are more electrons than protons, it is negatively-charged -if there are less electrons than protons, it is positively-charged.</p><p>Static electricity is an ______of electric charge on the surface of an object.</p><p>Law of Electric Charges: Charged objects exert an electric force: -objects with opposite charges ______each other ( + and - ) -objects with the same charge ______each other ( + and + or - and - )</p><p>If you bring a charged object toward a neutral one, it causes induced charge separation in the neutral object. The electrons in the neutral object move according to the law of electric charges and there is a force of attraction between the charged & neutral object.</p><p>A metal leaf electroscope can be used to detect charge. [See Figure 10, p.469]</p><p>There are many practical uses for static electricity: -electrostatic paint sprayers -electrostatic dusters & electrostatic precipitators [see 11.2] -laser printers [see 11.4] -photocopiers [see 11.6]</p><p>**Do questions #2-9 on page 471** 11.2 - Charging by Contact</p><p>There are different ways to charge an object: 1. charging by friction: -If you rub two objects together, ______will move from one object to another. The object that ______electrons gets a negative charge. The object that ______electrons gets a positive charge.</p><p>The electrostatic series [see Table 1, page 473] is a list of materials arranged in order of their tendency to gain electrons. When you rub two materials together, the material that is lower on the list will gain a negative charge because electrons will move onto it from the other material.</p><p>2. charging by conduction (direct contact): -If a negatively charged object touches a neutral object, some electrons will move from the negative object to the neutral object, giving the neutral object a ______charge. -If a positively charged object touches a neutral object, some electrons will move from the neutral object to the charged object, giving the neutral object a ______charge.</p><p>Grounding is connecting a charged object to a large body like the ______. It takes away the charge of the object by either adding electrons to or removing them from the Earth.</p><p>**Do questions #1,2,5,6 on page 477**</p><p>11.4 - Conductors & Insulators</p><p>Conductors are materials that ______the movement of electrons. e.g., metals, tap water, your body</p><p>Insulators are materials that ______or prevent the movement of electrons. e.g., plastic, wood, ebonite, glass, rubber **Do questions #1,6 on page 482**</p><p>11.6 - Charging by Induction</p><p>If you bring a charged object close to a neutral one (without contact), it causes electrons in the neutral object to move, resulting in an uneven charge distribution, causing a temporary charge. This is called charging by induction.</p><p>You can then charge an object permanently by induction by touching the charged object to the neutral one. [See Figure 3, page 487] **Do questions #2,6 on page 489**</p><p>11.8 - Electric Discharge</p><p>An electric discharge is the quick movement of electrons from one object to another. -for example: when you feel a shock when you touch someone or something; a ______bolt is also an electric discharge -lightning rods on buildings carry the electric discharge safely to the ground **Do questions #1,2 on page 495**</p>