Electricity and Magnetism Unit Study (II)

I decided it was time for another Electricity Unit mostly because Teddy had been asking me tons of questions about electricity, and has also been very fascinated with/scared of (those two things often go together) lightning lately. It was funny to realize that the girls haven't learned any of this either, since we last did this unit in 2014. Malachi claims to remember everything, but he was only 6, so I'm not sure I believe him. But he was like Teddy back then—very curious and inquisitive and serious about learning, and a FULL participant in everything we did, so maybe he does remember!

I also feel like I did a more complete job on this unit the previous time through. Abe and Seb both understood a lot about electricity already, and helped me figure out a lot of things! And they were very excited and eager to do all the activities, which is always helpful. I was surprised how much the girls liked working with the snap circuits, etc., too this time—but they weren't AS fanatical about it as the boys were back then. I think this subject was just of particular interest of both of those older boys!

Here is the pinterest board from 2014, with perhaps a few pins added this time: https://www.pinterest.com/marilynnielson/electricity-and-magnetism-homeschool-unit/

A good place to start when talking about electricity is with the structure of the atom, and by explaining how ions work. Here are the children playing the "pass the electron" game (we do something similar to this one: https://www.nationalgeographic.org/activity/circuits-friends/print/)

Here are some explanatory videos we watched:

Ions: https://www.youtube.com/watch?v=bnudaqeTyto
Atoms: https://www.generationgenius.com/videolessons/atoms-and-molecules-video-for-kids/

More activities we did last time: https://nielsonschool.blogspot.com/2014/04/electric-current-conductors-and.html

Luckily, we still had most of our electricity and magnetism supplies from last time. They're great to have around for homeschool in general. Here's the list of supplies I made last time, and links to where to get things. Annoyingly, some links are broken, but a google search for that item usually yields lots of choices.

Here are some other videos we used:

Intro to circuits (beware annoying narrators): https://www.generationgenius.com/videolessons/electricity-and-circuits-video-for-kids/?gclid=CjwKCAjwhMmEBhBwEiwAXwFoEW1-Ub4d055l4boFmt-kvSXoab4mptqupBftaK02wHecFK9qWMYfRhoC76IQAvD_BwE 

Make sparks http://www.learnplayimagine.com/2013/04/how-to-make-lightning.html

Slow motion lightning strikes: https://www.youtube.com/watch?v=KO3H285CFRo

The electric eel https://www.youtube.com/watch?v=z0M7_HPSi14

Make a telegraph machine https://www.energizer.com/science-center/how-to-make-a-simple-telegraph-set

Virtual coal power plant tour https://www.youtube.com/watch?v=2IKECt4Y3RI
Nuclear power plant tour: https://www.youtube.com/watch?v=_AdA5d_8Hm0
Hydroelectric: https://www.youtube.com/watch?v=Ki8kSB1ThJQ
Substation: https://www.youtube.com/watch?v=7Q-aVBv7PWM

You can learn a lot just by playing around with making your own circuits. The children had a lot of fun doing that in an open-ended way with all the supplies we had. Snap circuits are, of course, fun too, but they don't have the immediacy of a real circuit with a bulb and battery you add in yourself. 

More ideas for circuit exploration: https://nielsonschool.blogspot.com/2014/04/simple-foil-circuits-series-and.html

And some further study of switches and resistors: https://nielsonschool.blogspot.com/2014/04/resistors-and-switches.html. That link includes an explanation of three-way switches, which I had forgotten and had to relearn this time. Here's Daisy giving another explanation of it:

And a few more resources:

• Make a three-way switch https://www.youtube.com/watch?v=6_TpKdYeQaU

• Make paper circuits with pencil https://www.youtube.com/watch?v=BwKQ9Idq9FM
• Make foil circuits https://www.youtube.com/watch?app=desktop&v=qJDgl9eVpy8

Making a homemade light bulb is always fun! It's so dramatic when it burns out.

Instructions here: https://nielsonschool.blogspot.com/2014/04/homemade-light-bulb.html

Or you can refer to these pictoral instructions: https://www.wikihow.com/Make-a-Light-Bulb

We talked about batteries and made a voltaic pile. (You can also dissect a battery—see that same post)

See also:

• Voltaic pile https://www.sciencebuddies.org/science-fair-projects/project-ideas/Energy_p015/energy-power/make-a-battery-from-coins#procedure

• Hand battery https://www.exploratorium.edu/snacks/hand-battery

Success! The voltaic pile powered our LED.

I remembered that we all enjoyed making these slider cards last time, so we did that again. (Video tutorial here: https://www.youtube.com/watch?app=desktop&v=aurnw8C1aUc) The subject of the slider card was supposed to be something to do with electricity. Let us see if the children followed these instructions. Junie made a cool lightning storm.

Daisy showed a circuit working and explained how it worked.

Goldie drew…the Teddy Bears' Picnic?

And Teddy drew…a tree in summer and winter (plus a green bunny and an "I love you" for me. Sweet.)

Cleaning pennies is a cool demonstration. We also did a simple form of electroplating that was a little different than what we did last time. We had a buy a copper pipe at the hardware store to get our copper ions off of. A few weeks later, that pipe turned out to be the exact right size to replace a towel bar that had broken in one of our bathrooms. How lucky! :)

Some of our electroplated coins

Resources: 

• Clean pennies with vinegar https://sciencebob.com/clean-pennies-with-vinegar/
• or this https://www.thoughtco.com/chemistry-fun-with-pennies-602055

• Copper plating a nail https://www.youtube.com/watch?v=T3qhqTVssoo
• Or here: https://www.youtube.com/watch?v=gTjWkeSpRqk

• How Electromagnets work https://www.youtube.com/watch?v=cxELqN7wjS0

• How a doorbell works https://www.youtube.com/watch?v=1R5ED5qHWZc

We also tried our hand at making paper circuits with copper tape. 

(see instructions: https://www.sciencebuddies.org/stem-activities/paper-circuit#summary)

It was surprisingly tricky to make the circuit complete AND make it fit with the drawing you wanted to do! Daisy made a glowing penguin.

Teddy made a green-eyed bunny.

Malachi made…this

Junie made this terrifying monster

And Goldie made a really cool lightning storm!

Here are a few more links for studying magnetism:

• Making 3-D Magnetic Fields

• More magnet play

Electricity and Magnetism Supplies

For this unit, we had some of the basic components we needed on hand, and I ordered a few more. I was wishing someone would tell me all the sorts of things I would need so I didn't have to figure it out myself, and so I wouldn't be caught without something we needed. For that reason, I give you this list. You can pull batteries out of flashlights and improvise bulb holders, etc., but if you're a beginner and need guidance, I think the following things made up a pretty good basic electricity exploration set:

Alligator clips--get several so you can make different kinds of circuits

Tiny light bulbs--These work well with D batteries as the power source, and light bulbs are the easiest way to test if a circuit is working or not! Again, getting several will let you construct parallel and series circuits, etc. Also, it's nice to have extra in case you burn some out.

Bulb holders--Not totally necessary, but so much easier than holding or taping the contact of the wire to the bulb base!

Insulated copper wire--Nice and safe, but you'll have to scrape the insulation off the ends for your contact points. If you have the right tool (wire stripper?) it's probably fine, but we didn't. I finally used a butter knife (too sharp of a knife will just cut the wire!) to scrape-scrape-scrape, and that worked pretty well.

Bare copper wire--sometimes you want bare copper wire, like if you're making a dimmer switch and want to be able to connect the circuit at any point along the wire.

Magnet wire--good for making motors

6-volt battery--I like this because the terminals are so accessible and easy to clip wires to! 

D batteries--It's good to have a bunch of these on hand

Carbon-zinc batteries--safe for dissecting!
LEDs and resistors--fun to use in circuits, but because they use so little voltage, you sometimes have to use the included resistors as well (a 9-Volt battery will burn them out instantly)
Mechanical pencil lead---for a homemade light bulb

For exploring magnetism, any old magnet will do, but we also found these supplies really fun:
Iron filings--for sprinkling on paper or putting into oil to make magnetic fields visible, or just for giving your magnets funny furry beards. They're kind of messy but SO fun! And much easier than the "steel wool shavings" many instructions suggest substituting
Basic bar magnets--marked with North and South Poles
Horseshoe magnet--stronger than the bar magnets, and makes a different kind of field

I generally think getting things in "sets" is a waste, since they inevitably include things you don't need/don't like/are flimsier than you would have gotten separately---but these both looked pretty good, so we also got these two sets:

Motors and generators kit--because making the coils of wire big enough and sturdy enough to work in a generator is pretty hard, and this has that part done for you. You can see how the motor and the generator work in reverse of each other, and the magnets snap on to the sides so nicely. We thought this kit was very easy to use, while remaining useful because you can tell what's going on!

Maglev Kit--This probably could be made without a kit, but there was no way _I_ was going to be able to figure out all the components. And because my children LOVE maglevs, and had been wishing and wishing to make one during our Train Unit, I thought this kit would be worth our while. The maglev was really fun to make, and although it needs some adjustment to run perfectly (sanding off the sides, making the weight balance perfectly, etc), the process itself is fun enough to be worth it.

Also contact cement--you need this to go with the Maglev Kit

We also have (and love) this Snap Circuit set---and there are lots of other sets that look fun too! Someone gave us this one specifically about electromagnetism, and it's fun, but not that great on its own. I'd recommend the set above instead, because it does a lot more.

Resistors and Switches

After making some simple circuits, we were ready to learn about resistors. First we made a simple "dimmer switch" using a wire coiled around a pencil. (See here for supply list.) As you move the connection up and down the coiled wire (allowing the current to either go through a lot of wire, or just a little wire), you adjust the resistance and the light gets brighter or dimmer accordingly.

We also made a circuit that included a large piece of paper towel. The paper towel provides enough resistance to the current that the electricity doesn't even get through, and the bulb won't light. But if you wet the paper towel, it provides less resistance (water helps the paper towel become somewhat of a conductor) and the bulb lights---dimly. If you sprinkle salt onto the wet paper towel, you decrease resistance even further and the light glows quite brightly!

Next, we experimented with switches. Here is a simple on-off switch using a paper clip.

My favorite was the three-way switch, which is a concept I have never before understood. This is like a room in your house where there are two switches (one at each end of the room) to turn on the same light. Here's how it works: there are basically two circuits, a short one and a long one, and two switches that toggle between the two circuits. If one switch is "up" and the other is "down," neither circuit is complete and the light is off.

If both switches are "up," the shorter circuit is complete and the light turns on.

If both switches are "down," the longer circuit is complete and the light turns on.

Amazing, eh? I love it.

Simple Foil Circuits; Series and Parallel Circuits; Schematics

There are a lot of cool electronics kits you can get, and in fact we had been given some snap circuit kits earlier in the year, which I'd been saving for this unit---so we could have just started right in on those. I read lots of reviews on the snap circuits talking about how educational they were, and they ARE wonderful and we have loved them---but---my one problem with them is that they are somewhat far-removed from the actual workings of the electricity. By that I mean, all the actual wiring is enclosed in snap-able components, and while that makes for ease of use, it also makes the workings of the electricity somewhat more opaque (at least to me). I think once you understand what is going on, snap circuits are great, but for an introduction to circuits, I think there are better illustrations.

So, we started with what seems to me the very most basic form of a circuit: foil and a battery! (Here is a how-to video about foil circuits, if you need it.)

First we felt how the foil gets warm as a current passes through it

Then we added a tiny light bulb and watched it light up as electricity went through the circuit! (I will have a separate post about the materials we used for this unit.)

Next we set up circuits with batteries, bulbs, and alligator clips. We tried various configurations and learned about parallel and series circuits.

Parallel Circuit---note that the bulbs have the same brightness

Series Circuit---note the progressively dimmer bulbs as the current becomes weaker

The children also copied down a list of symbols used in wiring and circuitry schematics. They loved this---it's like a secret code!

Here are a few more resources for circuit symbols:

http://www.itclips.net/2012/04/03/going-from-schematic-to-breadboard/

http://dccircuit.wikispaces.com/01+Circuit+Symbols
http://guides.machinescience.org/mod/book/print.php?id=1312--scroll down on this page to see how a seven-segment display, like you see on digital clocks, etc, works. Very interesting.

Here's a short video about circuits

Also, these circuit worksheets from Teachers Pay Teachers are fun.

And we thought this article about circuits in your house was really interesting!