LESSON 3: What is electricity?

AIMS:

1.  What is electricity?

2.  What are some vocabulary words associated with electricity?

3.  What are conductors and and insulators?

MOTIVATION:

Read to students different books on electricity.  (Here is a small sample of books available for teachers on an elementary level)-

Discovering Electricity, Rae Burns, Troll Associates, 1982

Electricity, Keith Brandt, Troll Associates, 1985

Junior Science Book of Electricity, Rocco V. Feravolo, Garrad Publishing, Illinois, 1960

Show students different examples of electricity.  How do these pictures show electricity?  What are ways that electricity are used in the classroom?  In your homes?

The first picture is from http://ftschool.org/fourth/science/electric_magnet.html .  The middle picture is from http://library.thinkquest.org/11924/electricity.html and the last picture is from http://homepage.mac.com/tonyfarley/science/physics/physics.html

PROCEDURE:

1.  Have students find out what electricity is by researching it on line.  They can find information at the following websites: http://brainpop.com/science/electricity/  http://library.thinkquest.org/11924/ewhat.html  http://reprise.com/host/electricity/default.asp

The following website has a wonderful interactive component where the student can create an electron moving around the nucleus of an atom: http://colorado.edu/physics/2000/waves_particles/wavpart2.html

This excerpt explains what electricity is.  It was taken from

http://energyquest.ca.gov/story/chapter02.html

But what is electricity? Where does it come from? How does it work? Before we understand all that, we need to know a little bit about atoms and their structure.

All matter is made up of atoms, and atoms are made up of smaller particles. The three main particles making up an atom are the proton, the neutron and the electron.

Electrons spin around the center, or nucleus, of atoms, in the same way the moon spins around the earth. The nucleus is made up of neutrons and protons.

Electrons contain a negative charge, protons a positive charge. Neutrons are neutral -- they have neither a positive nor a negative charge.

There are many different kinds of atoms, one for each type of element. An atom is a single part that makes up an element. There are 118 different known elements that make up every thing! Some elements like oxygen we breathe are essential to life.

Each atom has a specific number of electrons, protons and neutrons. But no matter how many particles an atom has, the number of electrons usually needs to be the same as the number of protons. If the numbers are the same, the atom is called balanced, and it is very stable.

So, if an atom had six protons, it should also have six electrons. The element with six protons and six electrons is called carbon. Carbon is found in abundance in the sun, stars, comets, atmospheres of most planets, and the food we eat. Coal is made of carbon; so are diamonds

Some kinds of atoms have loosely attached electrons. An atom that loses electrons has more protons than electrons and is positively charged. An atom that gains electrons has more negative particles and is negatively charge. A "charged" atom is called an "ion."

Electrons can be made to move from one atom to another. When those electrons move between the atoms, a current of electricity is created. The electrons move from one atom to another in a "flow." One electron is attached and another electron is lost.

And this is what electricity is!

2.  Have students log on to http://ftschool.org/fourth/science/electric_magnet.html, http://curriculumvisions.com/electricity/electricityGlossary.html

to complete the following vocabulary database:

 WORD DEFINITION Circuit A circuit is a continuous path for the flow of electricity. Battery A device for turning chemical energy into electrical energy. Conductor A conductor is any material that will allow electricity to flow through it. Insulator Materials that do not allow the flow of electricity are called insulators.. Current An electric current is the flow of electricity through a conductor such as a wire. Static Electricity A kind of electricity made by friction. Positive and negative charges that are separated from each other and are not moving. Electric Current A kind of electricity produced when negative charges move along a path. Electricity A form of energy that can produce light, heat, and magnetism. Electromagnet An electromagnet is a controllable temporary magnet created by passing an electric current though a coil of insulated wire.

3.  Now that the students know what electricity, circuits, conductivity, and insulation are, it's time to do experiments!  The following will teach students how to make a circuit, and test for conducting and insulating materials.  (For student samples and pictures of these activities, click here).

Lab Activity 1:

 Problem:  How do we make an electric circuit? Hypothesis:  We think if we connect an electric receiver (light bulb) to an electric source (battery) through a wire, then we can make a complete circuit. Materials:  battery, battery holder, 2 pieces of insulated copper wire, light bulb and socket Procedure:  1.  Place the battery in the battery holder.  2.  Connect one end of the copper wire to the hole attached to one side of the battery holder.  3.  Connect the second copper wire to the other hole on the battery holder.  4.  Connect one end of the open wire to one side of the bulb socket.  5.  Connect the other open wire to the other side of the bulb socket. Observations:  Did the light bulb light?  Why?  What happens when you remove one of the wires from any point?  Why doesn't the bulb light now?  Draw a diagram of your completed circuit. Conclusion:  I learned that in order for a circuit to be made, an electric source must be connected by wires to an electric receiver.  One wire must leave the source, go into the receiver, and a second wire must leave the receiver and travel back to the source. This makes a complete circuit.

Lab Activity 2

Problem:  How can we test for conducting and insulating materials?

Hypothesis:  We think when we  pass an electric current through different materials if the material makes the bulb light, then it is a conductor; and if the bulb doesn't light, then it is an insulator.

Materials:  battery, battery holder, 3 pieces of copper wire, light bulb and socket, bag of various materials to be tested (paper clip, paper fastener, rubber band, plastic tile, button , glass marble, paper, wood, nail, screw, pencil, eraser, styrofoam, etc.).

Procedure:  1.  Make a circuit as in Lab Activity 1 except don't connect the second wire to the light bulb socket.  2.  Using the third wire, connect that to the other end of the light bulb socket.  3.  You now have to open ended wires.  4.  One at a time, take each material from the test bag, and touch each end of the open wires to the material.  Be careful not to let the wires touch each other!  5.  If the light bulb lights up, the material is a conductor.  If not, the material is an insulator.

Observations:  Complete the following chart:

Conclusion:  We learned that all metals are conductors and things like rubber, plastic, glass, and dry wood are insulators.

 Material Conductor or Insulator? paper clip conductor paper fastener conductor rubber band insulator plastic tile insulator plastic button insulator glass marble insulator wood insulator paper insulator nail conductor screw conductor pencil insulator (on wood), conductor (on metal band) eraser insulator styrofoam insulator

 Follow up Activities: 1.  Have students research about Benjamin Franklin, Thomas Edison, and other scientists who based their inventions on the use of electricity.  Let them write about one invention that uses electricity.  A good site to find research for this is http://ftschool.org/fourth/science/electric_magnet.html 2.  It's always a great learning experience for children to show their parents what they learned.  Have them make an electric circuit at home and test different objects for conductivity and insulation.  If necessary, lend them the materials for this assignment.

 OVERVIEW ASSESSMENTS RUBRIC STUDENT SAMPLES

 What is magnetism? What is a magnetic field? LESSON 3 What is electricity? What is an electromagnet?