BASIC ELECTRICITY

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BASIC ELECTRICITY

• CHAPTER 1
• ATOMIC STRUCTURE

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TERMS TO KNOW

• ALTERNATING CURRENT(AC)
• ATOM
• ATTRACTION
• CENTRIFUGAL FORCE
• CONDUCTORS
• DIRECT CURRENT (DC)
• ELECTRON
• ELECTRON ORBITS

• INSULATORS
• MATTER
• NEGATIVE
• NEUTRON
• NUCLEUS
• POSITIVE
• PROTON
• SEMICONDUCTORS
• VALENCE ELECTRONS

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HISTORY OF ELECTRICITY

• GREEKS DISCOVERED 2500 YEARS AGO
• USED PRACTICALLY ABOUT 100 YEARS
• AMBER BECAME CHARGED WHEN RUBBED WITH OTHER
  MATERIALS ATTRACTED THINGS LIKE LEAVES,
  FEATHERS, BITS OF CLOTH
• THE WORD ELECTRIC COMES FROM THE WORD ELEKTRON

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LIST A POSITIVE LIST B NEGATIVE
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STUDY OF ATOMS

• ATOM IS THE BUILDING BLOCK OF UNIVERSE
• ALL MATTER IS MADE FROM A COMBINATION OF ATOMS
• MATTER IS ANY SUBSTANCE THAT HAS MASS AND TAKES
  UP SPACE
• MATTER CAN EXIST IN THREE FORMS SOLID, LIQUID,
  OR GAS
• ELEMENT CANT BE DIVIDED INTO A SIMPLER SUBSTANCE

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STUDY OF ATOMS
THREE STATES OF WATER
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THREE PARTS OF AN ATOM 1.ELECTRON 2. PROTON
3.NEUTRON NUCLEUS PROTON AND NEUTRON NOTICE THE
CHARGES OF EACH PART
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PROTONPOSITIVE CHARGE
ELECTRONNEGATIVE CHARGE
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LAW OF CHARGES. Opposite charges attract and
like charges repel
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VALENCE ELECTRONS

• OUTER SHELL OF ATOM IS KNOWN AS VALENCE SHELL
• ELECTRONS LOCATED IN OUTER SHELL ARE VALENCE
  ELECTRONS
• THE VALENCE SHELL CANT HOLD MORE THAN 8 ELECTRONS

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COPPER GOOD CONDUCTOR BECAUSE OF ONLY ONE
VALENCE ELECTRON
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CURRENT FLOW HAPPENS WHEN ELECTRONS MOVE FROM
ATOM TO ATOM.
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INSULATORS HAVE 7 OR 8 ELECTRONS IN VALENCE SHELL
SEMICONDUCTORS HAVE 4 ELECRONS IN VALENCE SHELL
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CONDUCTORS

• THEY HAVE ONLY 1 OR 2 VALENCE ELECTRONS
• THEY GIVE UP THOSE ELECTRONS EASILY WITH LITTLE
  EFFORT
• THEY ALLOW CURRENT FLOW EASILY LOW
  RESISTANCE!!!!!!

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EXAMPLES OF GOODCONDUCTORS

• SILVER 1 VALENCE ELECTRON
• COPPER 1 VALENCE ELECTRON
• GOLD 1 VALENCE ELECTRON
• ALUMINUM 3 VALENCE ELECTRON
• PLATINUM 1 VALENCE ELECTRON

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INSULATORS

• MATERIALS THAT HAVE 7 OR 8 VALENCE ELECTRONS
• RESIST FLOW OF ELECTRICITY
• ELECTRONS ARE HELD TIGHTLY AND ARE NOT GIVEN UP
  EASILY

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EXAMPLES OF INSULATORS

• RUBBER
• PLASTIC
• GLASS
• WOOD

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SEMICONDUCTORS

• MATERIALS THAT HAVE 4 VALENCE ELECTRONS
• ARE NEITHER GOOD FOR CONDUCTORS OR INSULATORS
• USED TO MAKE DIODES AND TRANSISTORS
• COMPUTORS ARE FULL OF SEMICONDUCTOR MATERIAL
• SILICON AND GERMANIUM MOST COMMON USED

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METHODS OF PRODUCINGELECTRICITY

• MAGNETISMGENERATOR
• CHEMICALBATTERY
• PRESSUREPIEZO SENSORS
• HEATTHERMOCOUPLES
• FRICTIONSTATIC
• LIGHTPHOTO ELECTRIC

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REVIEW..

• OPEN THE BOOKS TO SUMMARY AT END OF CHAPTER.
• DO THE REVIEW QUESTIONS IN CLASS.