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Electricity.

Dear Subscribers:

While working on this issue of Science Weekly, I was captivated by the many aspects of electricity that literally leapt out at me. But the one that shocked me the most was how much the topic keyed on mathematics. Before reading more, think about this for a moment. Make your own list. Then compare it to mine. If I haven't addressed a particular "angle," please let me know (my e-mail address is at the end of this letter). I'll add it to my collection for future work on this and other topics.

Okay, are we ready? Here's my preliminary list:

* the number of appliances that use each of the two different types of electricity

* the number of batteries it takes to make some appliances work

* the wide range of battery sizes and shapes (geometry)

* the number of new electrically-powered appliances that come on the market each year

* the number of things that operate on electricity (e.g., appliances, lightning, our bodies)

* the number of jobs that either use or involve electricity (including that of our featured scientist)

* the amount of electricity that we use in this country and in other places around the world (we are talking billions of kilowatt-hours)

* the number of ways in which electricity is generated, and the ways we work to lessen our overall energy demands

* the EnergyStar[TM] appliance ratings and how much energy this initiative has saved

* how reading our home or school electric meters and electric bills provides for family math applications and discussions

And I've left the higher-level electricity and power computations for when the students reach middle and high school.

Yes, electricity is simply as much a part of our lives today as is eating, playing and sleeping. And the numbers prove it!

I hope this edition of Science Weekly sparks your students to an increased interest in science and math. It certainly generated a lot of interest in my mind.

Sincerely,

H. Michael "Mike" Mogil Editor-in-Chief E-mail: editor@scienceweekly.com

Background

If it were not for the wonders of electricity, modern life would be much different! Think about how many things you use that rely on electricity in just that first hour, right after you get up in the morning. Whether we have something plugged in, or are depending on batteries, our lives wouldn't run without electricity!

All objects in the universe are composed of atoms, and each atom is composed of subatomic particles. Protons, which carry positive charges, and neutrons, which carry no charges (neutral), are located in the nucleus (center) of the atom. The electrons, which carry negative charges, travel in rings around the outside of the nucleus. Electricity is the movement of electrons from a negatively charged place to a positively charged place. (See http://www.energizer.com/ learning/howbatterieswork.asp).

Static and Current Electricity

There are two types of electricity--current and static. To understand how to make electricity work for us, we have to know more about how electrical charges behave.

Static electricity involves the buildup of electric charges. Some objects obtain a positive (+) charge and others a negative (-) charge. When two objects have an opposite charge, they attract each other and stick together. When they have the same kind of charge, they move away from, or repel, each other.

If there are too many electrons in one place and too few in another, you may experience an electrical discharge or shock. This sudden, uncontrolled movement of electrons often happens when you put on a wool sweater or rub your sock-footed feet on some types of carpet. It also happens in the atmosphere as lightning, when raindrops move past each other (a gigantic discharge).

In current electricity, the electrons move along a conductor from one place to another. Current electricity is what we use when we plug appliances into electrical outlets and when we use batteries. Electricity flows along substances that are good conductors. Most metals are good conductors, because they allow electrons to travel along them with very little resistance. Poor conductors are called insulators. Insulators, like glass and rubber, are highly resistant and do not allow electrons to flow along them easily. We use current electricity to make everything run in our homes. It travels safely along wires that have a rubber or plastic coating or insulation. Dealing with current electricity can be dangerous, and even lethal, if not handled properly.

Circuits

Electricity can flow along two types of circuits. In a series circuit, all the objects requiring electricity to work are set in a line. Electricity flows from one object to the next, and so forth. If one of the objects in the line is broken, it stops the flow of electrons to the others. A series circuit is sometimes used on Christmas tree lights and is the reason why when one light is broken, the entire chain no longer works. Houses are constructed with another type of circuit--a parallel circuit. Parallel circuits allow one light in a house to be turned off, without affecting the flow of electricity to the others. In this type of circuitry, each object that requires electricity has its own wiring which connects to the main line.

How We Measure Electricity

In measuring electricity, several terms are used. Electricity is measured in amperes (amps), which are the rate of flow of electrons in a current. An instrument called a ammeter measures the current. Electrons are forced along a circuit much like water molecules are forced through a hose. The force pushing the electrons is called the electromotive force. This force is measured in volts. The term watts refers to the measurement of power in an electric circuit (watts = volts X amps). Our electric bills are based on kilowatt-hours (1 kilowatt = 1000 watts). A kilowatt-hour is the amount of electricity needed to light a 100-watt light bulb for 10 hours (10 hours X 100 watts = 1 kilowatt).

We measure our energy use by an electric meter on our homes. Have you read your meter recently? Do you read it each day or each week? Do you check its reading with what appears on your monthly electric bill? Depending upon grade level, you might want to see how many students have read their home's electric meter. This provides an excellent way for bringing science home. Have students work with their families to evaluate their energy use at home by reading their electric meters, and then try to find ways to reduce the amount they use. Another way to do this is by examining the EnergyStar[TM] ratings on appliances. To learn more about this program and other energy-saving/conserving opportunities please refer to our links page. (See Internet Resources, page 8.)

Generating and Saving Electricity

How do we get our electricity? For batteries, the electricity comes from within. From our electric outlets, it comes from electricity-generating plants. These plants are powered by fossil fuels (coal, oil and natural gas), moving water (hydroelectric dams and plants), tides, geothermal sources, the sun, wind and even the decomposition of organic (once living) material. Check with your local electric power company to find out more about "green power" and how individuals can actually sign up to buy energy from specific renewable sources.

Electric companies, who provide electricity to us are trying to produce as much energy as possible, while using less fuel and creating less pollution. That's why we are seeing more use of renewable energy sources like solar and wind power. Still, even these sources can have serious environmental impacts.

Our need for conservation and fuel-efficiency has brought about the use of new combinations of products that provide electric power. Solar batteries, products that turn themselves off and on, and new Hybrid EV cars are just a few. These hybrid electric vehicles use a small gasoline engine to constantly recharge the electrical battery. This makes them the most efficient cars on the market today.

Safety and Electricity

* Water and electricity don't mix.

* Current electricity comes from electric outlets; the only thing that belongs plugged into those is an appliance plug.

* When removing a plug from an outlet, ALWAYS hold the plug. Never yank the electric cord.

* Outdoors, get indoors whenever nature's electricity--lightning--is around. If you can hear thunder, even if you can't see lightning, lightning is nearby.

* ALWAYS be careful when using any type of electricity.

DID YOU KNOW??

Most energy-saving light bulbs last about 6 years. This is 8 to 10 times longer than an ordinary light bulb.

Level Pre-A

Main Concepts: Electricity makes things work. Some things need to be plugged into an outlet. Others use electricity from batteries

Picture Activity

Ask your students what electrical things they see in the picture with WHY FLY. Ask them what they use that needs to be plugged into an electrical outlet in order to work. Ask what things they use that run on batteries. Explain that when we use batteries, we are able to carry electricity with us wherever we go. Otherwise, we would always have to carry along very long electric cords. This is because electrical appliances need to be attached to a source of electricity to give them the power to work.

Vocabulary

This activity will help your students identify and discriminate the letters in the long word--ELECTRICITY. First review the "color" words and have them color the crayons here to match their colors. Read the directions to them and have them color in the correct light bulbs. They will find that all the letters occur twice, except for l, r, and y.

Weekly Lab

You need: balloons (at least one per student, blown up and tied), puffed rice (or styrofoam packing peanuts), wool or silk scarves (or a wool sweater or any large piece of wool or silk fabric). It may be a good idea to be sure you have additional adult supervision when using the balloons in class. Students should not share their balloons.

This lab experiments with static electricity. (Refer to the BACKGROUND section for more information.) You can explain that they may have already experienced static electricity if they have ever felt little crackling electric shocks after going down a plastic slide or rubbing their feet on certain types of carpet. After scattering some puffed rice on a table, have students pass their blown-up balloons over the cereal. Ask, "Is anything is happening?" Next, have them rub the wool or silk scarf or sweater on the balloon for 15 seconds, or for a count of 15. Students can try shorter or longer rubbing times based on the humidity of the air or other factors, and see if the response of the puffed rice changes. Discuss any variations that may result.

As students rub the balloon, electrons will move from the fabric to the balloon, making the balloon negatively "charged." Next, have them pass their "charged" balloons over (but not touching) the puffed rice again. The students should immediately start talking about what is happening. If they don't, initiate a discussion by asking, "What just happened? Why do you think this might be happening?" Explain that this isn't magic, but instead involves static electricity. You can talk briefly about positive and negative charges, introducing the "+" and "-" signs. Show the students a battery that shows "+" and "-" signs on it. Then, explain that the puffed rice, which carries a positive charge, is attracted to the balloon which carries a negative charge. This makes the rice hop up to the balloon. Students can also rub the balloons on the scarf or sweater and try to "stick" their balloons on a classroom wall.

You can then briefly introduce current electricity. Tell students that this is the type of electricity that makes TVs, computers and refrigerators work in their homes. Explain some basic safety rules for current electricity. You many want to tell them that safety plugs are used in the classroom to keep electricity in its place until a plug is used. Emphasize that current electricity can be very dangerous (see Safety and Electricity in the BACKGROUND section).

Math

Answers: The radio (A) needs 4 batteries; The clock radio (B) needs 2 batteries; The flashlight (C) needs 3 batteries; and the electronic game (D) needs 6 batteries. First have students draw lines from the four batteries to the correct appliance. Then have them count the total number of batteries needed for each appliance and write the number in the associated box. Explain that batteries come in many different sizes and shapes. Display some of these in class. Be sure students handle only one battery at a time.

Storytelling

Have students identify some of the many items that use electricity in this house picture. Which items need to be plugged in? Which run on batteries? Ask students, "How have you already used electricity today?" Have them think of some other electrical items that are not in the picture. This is also a good time to re-emphasize safety precautions and electricity.

To extend this activity, have students repeat the activity in the classroom. Ask, "Are there any items that are found at school, but aren't found in this house?"

Challenge

Answers: The lamp goes to plug C. Explain that cords attach appliances to electric power. To get electrical power, an appliance must be attached to an electrical source. Sometimes, this means using batteries, but most of the time, it means being plugged into an electrical outlet. A switch controls when electric power can flow to an item and when it can't. The switch can be on the wall or it can be on the appliance itself. Electricity will not flow when the switch is turned off.

Bringing It Home

Read these electricity-saving activities to your students. In class, discuss some other ways to save electricity. Then, have students go home and ask their families for some other ideas. Make a class list of all the electricity-saving ideas and use these to discuss why conserving (not wasting) electricity is important.

Level A

Main Concepts: Electricity makes things work. Some things use electricity from batteries. Some need to be plugged in.

Picture Activity

See TN Level Pre-A. There are four appliances that need to be plugged in--TV, computer, light and tabletop clock. There are four items that use batteries--TV controller, cell phone, portable radio, hand-held game.

Vocabulary

First, have students copy each of the letters of ELECTRICITY into the correct light bulb. Then have them review the "color" words and color the crayons to match the color, or color word, next to it. Finally, have them color in the correct light bulbs. All letters are "doubles," except for l, r and y.

Weekly Lab

See TN Level Pre-A. While the puffed rice is still clinging to the balloon, have students put one finger near (but not touching) the cereal. Have them tell what happened when they did this. Discuss that the cereal pieces were repelled (pushed away) by the electric charges on their finger. Explain that the balloon carries a negative charge and the puffed rice carries a positive charge, and that opposite charges attract. If the puffed rice is repelled by the student's finger, then the finger must be the same charge as the puffed rice (positive).

Math

Answers: The portable radio (A) needs 2 + 2 = 4 batteries; the flashlight (B) needs 1 + 2 = 3 batteries; the electronic game (C) needs 3 + 3 = 6 batteries. If you have similar appliances, you might bring them to class and show students: how the battery compartment needs to be filled with batteries; how only the correct size batteries fit; and why the battery charges must line up properly. Put the batteries in backwards (if possible) and show that the device doesn't work. Then, put them in correctly and show that it does.

If you have a small, hand-held battery checker (e.g., RadioShack's[R]--Catalog #: 22-096--Easy-to-Read Battery Checker for about $10), you can easily show how to determine a battery's charge level.

Writing in Science

Have students identify some of the many items that use electricity in this house picture. Which items need to be plugged in? Which run on batteries? Are there other things that use electricity at their home? At school? Make a class list of the two groups of electric devices.

Have students draw something from home that uses electricity. Have students write two sentences that tell about how they use electricity at home.

Challenge

See TN Level Pre-A. Answers: Circle C for the lamp; Draw a box around B for the TV; and draw an "X" on A for the vacuum cleaner.

Bringing It Home

See TN Level Pre-A. Talk about the conservation actions that might be used at home. Discuss how these might be used at school. If possible, do at least some of these.

DID YOU KNOW??

There is "hot" and "cold" lightning. "Hot" lightning can reach 50,000[degrees] F (27,760[degrees] C); "cold" lightning isn't really cold, as its temperature can still be around 15,000[degrees] F (8,316[degrees] C).

DID YOU KNOW??

According to NOAA, the total amount of energy release by the condensation process in a hurricane can reach 200 times the world-wide electrical generating capacity each day!

Level B

Main Concepts: Electricity makes things work. Some devices use electricity from batteries. Other appliances get electricity from electric outlets. Switches control how electricity flows.

Vocabulary

Three words hidden inside ELECTRICITY (without mixing up the letters) are city, elect and electric. When the letters are mixed up, students should be able to find at least three words from this list: yet, try, tree, ice, rice, icy, tire, cry, eel, lee, reel, let and letter. You may want to use some or all of these as vocabulary building words.

Weekly Lab

See TN Level A.

After Step 1, you should have students place their uncharged balloon over the puffed rice. What did they observe? Have them record their observations in their science journal.

After Step 2, students should record their predictions or hypotheses in their journals.

After Step 4, have students record what actually happened.

Repeat for the packing peanuts. Students should record both predictions and observations.

Repeat for the salt and pepper mixture. Again record in journals. What did the students observe?

Have them discuss similarities and differences among the experiments.

To extend the activity, have students rub the balloon on a scarf or other object and stick their balloon on a wall. Did the balloon stick? How long did it stay there?

Students may also want to try using static electricity to try and move an aluminum soda (pop) can (lying on its side) or other objects.

NOTE: If a balloon becomes uncharged, the student simply has to rub the balloon on the scarf again. As long as the balloons don't get wet, they will recharge.

For further investigation, spray a few drops of water from a plant mister on a balloon and see if the students can recharge the balloon with a few rubs? The wetness makes moving electric charges from one item to another difficult to impossible.

You may also want to send students home to check with their families for examples of static electricity. Does rubbing some pieces of clothing together create static electricity? What about clothes drying in a clothes drier? Are they full of static electricity? What does their parent place in the clothes drier, or use in the laundry, to reduce static electricity build-up?

Answer: Fabric softeners, such as Bounce TM are among products that are used to reduce "static cling."

Students can also get under their covers at night (especially when it is very dry inside) and make a lot of motions. If the room they are in is darkened, they might even be able to see small electric discharges.

Math

Answers: 4 + 3 + 6 + 8 = 21 batteries. If the student used all 11 batteries, B and D would work. But, if the student used some of the batteries (up to 11), A and C; A and B; and B and C would work. (Some batteries would not be used.)

Writing in Science

See TN Level A - BRINGING IT HOME.

Go over these electricity-saving activities together. Discuss other ways they can save electricity. Then, have students go home and ask their families for some other ideas. Make a class list of all the electricity-saving ideas and use these to discuss why conserving (not wasting) electricity is important.

Most electricity comes from power-generating plants. There is probably one not too far from your school. Some of these plants create power by burning coal; others generate power though the use of hydro-electric, nuclear or wind power; still others convert heat from decomposing plant and waste matter to produce electricity. Sunlight can also be used to generate electricity through solar cells.

In late 2003, the first commercial tidal power station opened in Norway. This operates in much the same way that a windmill captures wind, except that it uses the movement of water. The prototype (or model) tidal mill will only produce 300 kilowatts of electricity, enough to power about 30 Norwegian houses.

Many of these energy sources cannot be renewed (this means that once they are used up they are gone forever). Some of the energy sources cause pollution or harm other parts of the environment.

Talk about the conservation actions that might be used at home. Some additional ones include: only turning on the dishwasher when it is full; using low-wattage or energy-saving light bulbs; using air conditioning only when necessary; wearing warmer clothes in winter, and keeping the temperature at home a few degrees cooler.

Discuss how these might be used at school. If possible, do at least some of these.

To extend this activity: you may want to have your students create posters that show students, teachers and/or parents actually doing things to save electricity. Be sure each poster has a written message about saving electricity. Post these in the class and in hallways.

If you have a newsletter or a web page on which you share information with parents, you might showcase this effort and ask parents to get involved, too. Include photographs of the students in action making their posters and/or helping to save energy.

Challenge

Answers: Circle C for the lamp; draw a box around B for the TV; draw an "X" on A for the vacuum cleaner; draw a "[check]" on D for the drill. Explain that cords attach appliances to electric power. To get electrical power, an appliance must be attached to an electrical source. Sometimes, this means batteries, but most of the time, it means being plugged into electrical outlets. A switch controls when the electric power can flow to the item. The electricity will not flow when the switch is turned off.

Bringing It Home

Answer: lightning. This activity can be done at home or in class. Go over the sample together to make sure everyone understands how to solve this puzzle. Then, have students take it home and do it with their families tonight. Ask what a light bulb over someone's head in a cartoon means. It shows that someone has just had a great idea or has just figured something out.

To extend this activity: have students draw a picture of themselves with a light bulb above their head and write a story about it.

Level C

Main Concepts: There are two forms of electricity, static and current. The electricity that makes things work in our homes is current electricity. Some things use batteries, while others need to be plugged into outlets. A completed electric circuit is needed to make current electricity work.

Vocabulary

Answers: 1) moon 2) spoon 3)phone 4) bone 5) monkey 6) throne 7) pony 8) money. Switches turn the flow of electricity "ON" and "OFF." Ask students to think of some other words with "ON" in them.

Weekly Lab

Explain that there are two types of electrical charges: a negative charge (-) and a positive charge (+). Show students a battery to find these symbols. Explain that rubbing the balloons with the wool or silk scarf (or the wool sweater) causes both balloons to become negatively charged. Since both have the same charge, they will be repelled (move away) from each other. When the paper is placed between the balloons, they are both attracted to the paper (which has a positive charge).

To extend this activity: remove the paper and see if the balloons will again move apart. Then spray each balloon with a light mist of water. Observe what happens. The balloons will move together. Since water is composed of two hydrogen atoms (positively charged) and only one oxygen atom (negatively charged), the water lessens the charge separation that existed.

BONUS: The key is the negative charge on the balloon. Everything will be attracted to the balloon. To move the can, lay the can on its side. After charging the balloon, place it next to the can lengthwise and slowly move the balloon away from the can. The can will roll toward the balloon.

Math

Answers: 1) lightning 2) telephone 3) light bulb 4) battery.

Writing in Science

Help your students break this unusual word into smaller parts (for example electro-phone trono-nator), so they can decide on the correct pronunciation for it. Then, have students work in small groups and brainstorm ideas about what this invention might look like and what jobs it can do. Or, have students do the activity individually and then share their ideas in small groups. Post pictures for further discussion.

To extend this activity, some students may want to build models of their appliance using readily available materials from the classroom or from home.

Challenge

See student Level E page 4.

Puzzle

Allow students to search for the solution themselves. If any students have difficulty, explain to them that it will be easier to initially complete the circuit by working backwards from the lamp (one light instead of three plugs). Once the correct circuit is found, have students retrace the path from the outlet to the lamp to simulate the flow of electricity.

DID YOU KNOW??

Researcher, Lew Urry, who became the "father of the alkaline battery" in 1959, died in October, 2004. His prototype of the alkaline D-cell battery now resides in the National Museum of American History, in the same room as Thomas Edison's light bulb.

Level D

Main Concepts: There are two forms of electricity, static and current. The electricity that makes things work in our homes is current electricity. Some things use batteries, while others need to be plugged into outlets. A completed electric circuit is needed to make current electricity work. Lightning is a form of electricity. Electricity also helps our brain and heart to work.

Vocabulary

Answers: 1) batteries; 2) static; 3) charge; 4) electron; 5) negative; 6) electricity

Weekly Lab

See TN Level C.

Math

Answer: An electric eel can produce an electric shock large enough to kill a horse.

Writing in Science

See TN Level C. This writing activity requires students to explain HOW the appliance does its jobs. This can be done in paragraph form or via step-by-step instructions. If a student is able to create an easy-to-understand set of step-by-step instructions, use those as a model to explain the process to other students.

Challenge

See student Level D page 3. To extend this activity see TN Level E--WEEKLY LAB.

Meet the Scientist

If any class parent is involved in an electricity-related profession or job, you may want to invite them into class to tell about their work. Some possible job activities include, working on electricity distribution for an electric power company, being an electrician, using electricity to perform automobile testing, and using electricity in medical testing.

Level E

Main Concepts: An atom is composed of neutrons, protons and electrons. Electricity is the movement of electrons along a completed circuit. There are two types of electricity, static and current. Lightning is a form of electricity. Electricity also helps our brain and heart to work. Electricity flows more easily through some materials called conductors; insulators prevent the flow of electricity.

Weekly Lab

See TN Level D--CHALLENGE.

Math

The graph shown in the student issue is known as a double-Y graph. There are two variables plotted on the vertical or Y-axis. Sometimes, the data is plotted as two line graphs; at other times, the data is shown as two different types of graphs to make it easier to see the data. The data for the X-axis are matched.

If students haven't done this type of graphing yet, first have them plot data on the leftmost Y-axis, as they would normally do.

Then explain that you will be adding a second Y-axis (on the right-hand side). Based on the data set, the scale may match the left-most scale (as it does here) or the scale can be different.

Then have students plot their second set of data using the rightmost scale.

After plotting the two graphs, students should be better able to see the relationships between the two Y-variables.

NOTE: the graphing could be done in a computer program such as Excel[TM]. We suggest that students carry out this activity by hand to better understand the process, especially if they have never done a double Y-axis graph before.

Writing in Science

See TN Level D.

This writing activity requires students to not only explain, but to sell, their new product. Understanding what salespeople do, and determining its truth or value, is a very important life skill.

This activity also requires team-building and the use of good presentation skills.

As a class, discuss which presentations were the most believable and the reasons for this. Conduct a class poll to see which sales pitch was the most effective.

FYI--Furthering Your Interests

If students go to a store with their parents, be sure they know to ask the store manager for permission to carry out the measuring activity.

Discuss the different types of batteries (size, shape, function) with students.

Meet the Scientist

See level TN Level D.

If any parent is involved in an electricity-related profession, they may be able to bring some tools that they use and explain their functions to students. This might include an oscilloscope, ammeter, battery tester or circuit tester.

Weekly Resources

Helpful Sources for Planning Your Science Weekly Classroom Activities

Recommended Resources

* Bach, Brenda. Electronics Lab. San Diego: Silver Dolphin Books, 2001

* Baker, Wendy, et. al. Electricity (Make it Work! Science) Chanhassen, MN: Two-Can Publishing, 2000

* Berger, Melvin. Switch On, Switch Off. New York: HarperTrophy, 2001

* Bridgman, Roger Francis. Electronics: Eyewitness Books. New York: DK Publishing, 2000

* Gibson, Gary. Understanding Electricity. Brookfield, CT: Copper Beech Books, 1995

* King, Rob. Electricity: Real Science Made Easy. San Diego: Silver Dolphin Books, 2003

* Parker, Steve. Electricity: Eyewitness Books. New York: DK Publishing, 2000

* Slone, G. Randy. Understanding Electricity and Electronics. New York: McGraw-Hill, 2000

Internet Resources

You will find a complete listing of Internet resources on Science Weekly's web site at: http://www.scienceweekly.com/vol21.3.eletricity.html There you will be able to click on the available links to take you directly to the source sites.

National Science Education Standards and Benchmarks

Please also refer to Science Weekly's web site pertaining to National Science Education Standards and Benchmarks.

Imagine the world without electricity (elec-tric-i-ty). There wouldn't be any lights, computers, televisions, microwave ovens, CDs, or refrigerators. Some things would take a lot longer to do without electricity. There would be some things we could not do at all.

In order to work, some things need to be plugged into an electrical outlet (out-let). Others get their power from batteries (bat-ter-ies). Batteries let us carry electricity around with us wherever we go. It makes electricity portable (por-ta-ble).

Static Electricity

For electricity to work for us, we need to know how its electrical charges behave. For example, the electrical charges in static (stat-ic) electricity stay pretty much in the same place most of the time. Sometimes, there may be a sudden, uncontrolled movement of electricity. You may have felt this as an electrical discharge (dis-charge) or shock. This often happens when you put on a wool sweater or rub your sock-footed feet on some kinds of carpet. It also happens in the atmosphere as lightning (light-ning). Static electricity is not controllable!

Current Electricity

Current (cur-rent) electricity is the controlled movement of electrical charges. You are using current electricity every time you turn on a switch to activate a battery-operated appliance (ap-pli-ance). This action controls the movement of electrical charges along a circuit (cir-cuit). Most electric appliances in your home run on current electricity. You must be very careful with this type of electricity, because it can be very dangerous.

As you can see, electricity is all around you. It is in batteries, plugs, in the air and on your clothes. But, it is also in your body. Small amounts of electricity help your brain and heart to work.

DID YOU KNOW??

The first words Thomas Edison recorded on his phonograph were: "Mary had a little lamb."

DID YOU KNOW??

Much of the credit for the electrical world in which we live today can be traced back to Thomas Alva Edison. Edison patented some 1,093 inventions, including the incandescent light bulb, the phonograph and the "kinetoscope," a small box for viewing moving films.

Vocabulary

Switch ON your brain power! Fill in the missing letters.

1) - O N

2) --- O N

3) -- O N -

4) -- O N -

5) -- O N ---

6) --- O N -

7) - O N -

8) - O N -

DID YOU KNOW??

Electricity is very good at sending sound signals.

DID YOU KNOW??

Solar panels convert the sun's light into electricity.

DID YOU KNOW??

An electric eel can produce an electric shock powerful enough to kill a horse.

Weekly Lab

Have you ever felt a little shock when you put on a wool sweater or rubbed your feet on carpet? This is called static electricity. Let's make some more!

You need: 2 balloons (blown up and tied), 2 pieces of string (each about 2 ft. long), a wool or silk scarf or a wool sweater, and a piece of stiff paper

Step 1: Tie a piece of string to the end of each balloon.

Step 2: With a partner, rub each of the 2 balloons with a scarf 15 times.

Step 3: Now hold the ends of both strings together so the 2 balloons hang down. What happens to the balloons?

Step 4: Next, slide the piece of paper between the balloons. What happens now?

Bonus: Ask your teacher, or other adult, to help you by setting up 4 stations, each with a paper plate (or an inverted, 8" diameter or larger, plastic lid); and, with A) some puffed rice; B) some B. packing peanuts; C) an empty soft drink can; and D) a mixture of salt and pepper.

Rub your balloon on the scarf, again. Then, place the balloon over each plate (or lid) in order. What happens? Can you explain why? Record your observations and ideas in your journal.

DID YOU KNOW??

The first definite statement about static electricity was probably made in 585 BCE. Thales of Miletus (a flourishing commercial city in what is now part of Turkey) had observed that loadstone attracted iron.

DID YOU KNOW??

On April 29, 1879, in Cleveland, Ohio, electric lights were used for public street lighting for the first time.

Math

The capital letter tells you what row to go across. The number tells you what column to go up. You will find the letter you need where they meet!

Sample: D5 = n
1. Ben Franklin proved that - - - - - - - - - is electricity.
 C2 B3 A3 E2 A4 D5 B3 D5 A3

2. Alexander Graham Bell invented the - - - - - - - - -,
a machine that changed sounds A4 A1 C2 A1 E3 E2 B2 D5 A1
into electrical signals.

3. In 1879, Thomas Edison invented the - - - - - - - - -.
 C2 B3 A3 E2 A4 D3 B4 C2 D3

4. In 1800, Alessandro Volta made the first - - - - - - -
 D3 C4 A4 A4 A1 E5 D2


DID YOU KNOW??

The word electricity comes from the Greek word elektron, which means amber.

Writing in Science

Today's the day!

The fantastic new ELECTROPHONOTRONONATOR is being displayed for the very first time ever! It is the newest electrical appliance of its kind to go on the market. It does 3 jobs in 1 ... and in a fraction of the time. We know everyone will want to have one of their own right away!

What is an ELECTROPHONOTRONONATOR?

Draw a picture of one. Label all of its parts. How does it work? What are the 3 jobs it can do?

DID YOU KNOW??

According to NOAA, the total amount of energy released by the condensation process in a hurricane can reach 200 times the world-wide electrical generating capacity each day!

Challenge

Make your very own electrical circuit. Set up your wires and battery to look like the picture.

You need: 1 small Christmas tree light with the wires attached," or a small bulb and bulb holder; 1 battery (AA, C, or D)

* To make your electrical circuit, you need an adult to help you carefully remove about 1/2 inch of the coating from the ends of both wires. You will see the metal wire inside.

* Hold the coated part of the wire and place one end on the positive (+) side of the battery and the other end on the negative (-) side.

* Electricity will travel from the negative side of your battery through the wires. It will go past the light and turn it on. Then it will flow through the wires to the positive end of the battery. This completes the circuit.

* If you take one of the wires off the battery, the circuit will be broken, and the light will go off.

* Electricity in houses and in batteries has to flow through a complete circuit to work.

Adult supervision required.

Please see Teaching Notes before beginning this activity.

DID YOU KNOW??

Today's light bulb got its shape when Thomas Edison dropped a screwdriver on an early light bulb model. This accident changed its shape and caused it to burn brighter!

DID YOU KNOW??

Lightning is electricity. To measure how far away lightning is from you, count the seconds between the lightning flash and the rumble of thunder. Every 5 seconds equals 1 mile between you and the lightning.

Puzzle

To work, this lamp needs electricity. Which plug will help complete the electric circuit?

[ILLUSTRATION OMITTED]
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Article Details
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Author:Mogil, H. Michael
Publication:Science Weekly
Date:Nov 29, 2004
Words:6399
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