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!

Electric current, Conductors, and Insulators

After static electricity, we went on to current electricity. First we played a game where we showed how current flows (emphasizing the point that it isn't a thing that moves along, but energy--an impulse). Everyone held a stuffed animal and we pretended the animals were electrons. You were only allowed to hold one animal at a time, so when I introduced an extra stuffed animal into the system by handing it to one of the children, they had to hand off their other animal to make sure they still only had one. We passed the "current" along the line, and then talked about how if the energy goes down a line, it has to stop when it reaches the end. But if it goes around in a circle, it can keep flowing and flowing. We also showed how an insulator works---if you insert another person into the circle, and that person CAN hold more than one electron, then when the current gets passed to him, he just holds onto it and it stops. In our game, people who easily pass electrons along are conductors, and people that hold onto electrons (or don't accept new ones) are insulators.

Then we did a lab testing different materials for their heat-conductivity. (Idea from here.) We boiled water, then poured it into identical glass jars that were wrapped with various materials, and noted the starting temperature. We then measured the temperature of the water after 20 minutes to see how much heat was kept in by the wrapping. (Our wrapping materials were foil, bubble wrap, fleece [I put felt on the lab sheet, but I couldn't find my felt so we used fleece instead], cotton cloth, paper bag, wrapping paper, and water---the jar of water was in another, bigger, jar of water.)

Here is the Lab sheet I made for us; feel free to use it.

We had a lot of fun testing these things and even some surprises (the foil was a lot better insulator than we predicted---maybe because of the air trapped in its wrinkles? or its thinness?).

Static Electricity and Ions

We started this unit with static electricity, and to understand that, you first have to understand ions. We learned about ions when we studied nuclear energy, but it was good for us to review it. (I think I finally have it down now, but I tend to get ions and isotopes mixed up, so a reminder is always helpful for me.) We made little diagrams using fwuffballs to represent the subatomic particles. We showed how an atom losing an electron could create charged particles, either positive or negative.

There are lots of fun things you can do with static electricity and a balloon. There's picking up tiny bits of paper, of course . . .

Or making a stream of water bend

Or sorting salt and pepper (if you get the balloon just the right distance away, the lighter pepper jumps up to the balloon while the heavier salt remains on the plate).

You can repel a piece of tape with another (rubbed) piece of tape

But maybe our favorite thing is just making people's hair stand up!

Also, here's a nice video of a lightning strike.

And here is a fun video showing how to light up a fluorescent bulb with static electricity.

Electricity and Magnetism Unit Schedule and Lesson Plan

The children really, really wanted to learn about electricity, so I finally buckled down and planned this unit. It seemed like a really overwhelming subject to me at first (and it is, even if you're just doing the basics like we were), but it got easier as I went along. I realized as I was preparing that electricity and magnetism really go together, so the Electricity Unit grew into an Electricity and Magnetism Unit. All the better! We love magnets. :)

Here's a list of most of the materials you need for this unit, plus links to buy them online.

Below are some electricity and magnetism resources that didn't fit anywhere else. You can also look at my Electricity Unit Pinterest Board.

I really had to do a lot of reading before I FINALLY got it straight in my mind what the difference between volts, amps, ohms, and watts is. Here are some resources for that:

http://science.howstuffworks.com/environmental/energy/question501.htm

http://www.candlepowerforums.com/vb/showthread.php?9200-Amps-vs-Watts-vs-Volts

http://www.ducksters.com/science/electricity_102.php---some good electricity basics

http://www.physics4kids.com/files/elec_current.html

Robert Krampf's electricity show is really fun (subscription required---it's worth it! We love Robert Krampf and use his site all the time)

We loved this interactive animation for helping us understand AC and DC.

And here's a video that talks about the differences between AC and DC, and the contributions of Edison and Tesla to each.

LOVE this video explaining transistors and semiconductors. So clear!

Building a telegraph looks fun---we did something similar with the snap circuits. This could go with a lesson on the transcontinental railroad, too.

We spent a day talking about electricity in animals (we had some good books on the subject) and this article was interesting too.

And here's a short video about electric eels

Seb's illustration of the electromagnetic spectrum

Making paper model trains

These paper steam trains (printable files here, here, and here) were easy to make, since they are basically just paper boxes. But they started a larger trend. I told the boys I had seen more complicated paper models, but they took more time and precision to make, so we weren't going to do them right then. After they begged and begged, I finally said maybe we could try them another day. 

These more complicated models are of the TGV (high-speed train in France and other parts of Europe) and building them took a little more supervision from me at first. They are really cool, once built---much more detailed and realistic than the other paper trains we'd made.

Abe's TGV

Sebby, especially, became more and more obsessed with them. Once he had built a few, they weren't too hard, although he used tape instead of glue for the trickiest folds. For several weeks he was working on one of the TGV cars during every spare moment! He even added the pantograph to the top (the paper model omits that detail, to Seb's disapproval) . . .

and made a system of track and catenary wire for them to run on.

He experimented with making his own models too.

But eventually, he came back to printing out model after model from this site, which has dozens to choose from.

The models have all the different cars to print for each type of TGV, so eventually he got an entire train assembled, and then another. I think now he has made nearly every type on the website. It was really fun to watch him getting better and better at it as he went along.

Eventually Seb made a display case (with informational panel) to hold his favorite TGV power cars. He includes the proper pronunciation (we pronounce it the French way, "tae-zhae-vae") since he does NOT approve of saying "tee-gee-vee"! :)

Here are the power cars resting on their high-speed track, with lovely mountain scenery in the background.

Circus Train craft

On the day we talked about specialty trains, we also made this Circus Train out of butter boxes. (We also watched a Circus Train episode from Extreme Trains---very cool.) Each child made their own train car (and Seb also made the locomotive). We just cut out squares from both sides of each butter box, then drew animals to put inside. Last, we taped on straws to make bars so the animals wouldn't get out!

We read Curious George Rides A Bike to remember what circus train cars look like (although in that book, they are actually trailers pulled by a truck, not train cars):

Circus Bear

Circus Birds

Circus Monkey and Snake

Circus Penguins (Daisy made these---the Daddy Penguin, on the right, is working at his computer and wearing headphones.)

Train Play

As you can imagine (and as if they needed any further encouragement), the children did a lot of playing centered around trains during this unit. It was fun to see what they came up with in their free time!

(This was a failed attempt at making a high-speed train---Seb thought he could reduce the friction between the train car and the ground by getting everything wet. The cardboard didn't hold up to that very well.) :)