Tag Archives: experiments with balloons

Science: Electricity

There were so many good ideas of ways to explore energy, that I knew immediately this would be a two week topic.  This week for our activities we focused mostly on static electricity as well as began looking at current energy through batteries.

But, as always, we started by reading books and watching videos.  There’s no shortage of resources for electricity, so let’s get to it.

  

All of our traditional sources served us pretty well here.  The Magic School Bus offers the classic book The Magic School Bus and the Electric Field Trip, which does not have a corresponding episode.  Let’s Read and Find Out gives us Switch On, Switch Off which is a perfectly good option.  There are many other series we found as well.  However, the best title by far was the book Flick a Switch: How Electricity Gets to Your Home by Barbara Seuling.  This might also be a good time to revisit the Loreen Leedy book we loved so much, The Shocking Truth About Energy, since it focused a great deal on how energy eventually ends up as electricity.

Videos also gives us a lot of options.  The Magic School Bus has an episode about electricity called “The Magic School Bus Gets Charged.”  Oddly, it revolves around Valentine’s Day (it plays on the idea of “attraction” – get it?).  Bill Nye brings us two different topics, electricity and static electricity.  Since we were working with batteries this week, we also watched a couple of videos about batteries.  Below, you can see the How It’s Made episode about batteries.  Also, we found this cute school video about how batteries work.  The terminology was way over the kids’ heads, but they still thought it was cute.  I feel like school video projects are really high schoolers’ gift to Youtube.  We adored that one about Lego Newton.  Sometimes I watch them and think, “Maybe one day my kids will make science videos with Legos for Youtube!”  Oh, but I digress.  Here’s another video, this one about the iconic story about Benjamin Franklin’s famous experiment with electricity.

Now for the experiment books.  We used several good experiments from The Science Book of Electricity by Neil Ardley.  Bernie Zubrowski also gave us a solid entry with Buzzers and Blinkers, though most of it was above the kids’ heads this go around.  We had several other electricity books out, but the one I enjoyed the most by far was the book Power Up by Sandra Markle.  This book had the best, simplest ways for kids to play with electricity and batteries.  As you’ll see below, all we needed to get started was a battery, a flashlight bulb and some tin foil.  It also put things into a sort of puzzle context and invited kids to play with the concepts more than most of the other books, which were more formulaic experiments.  I wasn’t familiar with the author, but she has a newish blog about writing nonfiction for kids that I thought was actually pretty good.

We began with our notebooks and reviewed a bunch of ideas about electricity.  We talked about how it’s a form of energy that can be easily turned into other forms of energy.  We talked a little about atoms charges.  Atoms is something that the kids are vaguely familiar with from a number of sources, but we haven’t officially covered it and it’s not solid in their minds really.  I’m hoping I didn’t oversimplify too much when I talked about how parts of the atoms “get excited” and end up moving around, which leads to electrical energy.  Perhaps we’ll revisit this topic next year after we have a firmer understanding of atoms.  Finally, the kids drew something that uses electricity.  Three of them drew TV sets and one drew a vacuum cleaner.  Hm.

Next, we did three simple experiments with balloons and static energy.  I began by letting the kids show me what they knew about static and balloons by just giving them the balloons.  With no instruction, they all rubbed them on their heads and asked if their hair was standing up.  It was.

Next I showed them a few tricks.  We rubbed the balloons on the wool rug and a wool sweater to get a better charge then used them to bend the water coming from the tap in the kitchen.  It’s a slight bend, but definitely there.  Here’s a version of that using a comb.  We also tried to get two balloons to hang together, but discovered that when they are both charged, they resist each other.  That experiment is here but I’ll add one trick to it, which is that if you put a piece of paper in between the balloons, then they’ll switch and attract each other.  Finally, we did something a bit like this experiment where we used the balloons to pick up small scraps of paper.  I made it into a small contest where the kids had to see how many they could each get with their balloons.

All of that led to a nice discussion of positive and negative charges.  We talked about attracting and repelling.  I handed them each a battery and let them look at it.  We talked a little about how we were about to experiment with current energy, but that current energy can be pretty powerful.  We talked about safety with household electricity and with batteries before going to experiment with the batteries.

I gave them the aluminum foil strip (which was backed with tape and folded to help it not easily rip), the battery and the flashlight bulb, which was a 2.4 volt bulb.  You can buy one at Radio Shack if all your flashlights are LED (which ours almost all were!).  I told them to try to make the light bulb come on without anything else.

This is where BalletBoy’s Snap Circuits training came in handy.  Snap Circuits is this great toy that lets kids explore circuits and electricity.  I got the kids Snap Circuits Jr. back in the fall as one of our beginning of the school year things.  The junior level lays out every project very clearly so kids are basically just following directions.  Any kid who can build a basic Lego set can do it (so don’t mind the age 8 and up label, I suspect many kids could begin to appreciate this at 5 or even 4 if they were good with putting things together).  However, over time, kids begin to figure out what works.  BalletBoy likes puzzles so he loves this one.  You can upgrade the junior kit to a regular one by purchasing a small kit.  There are also millions of different add ons you can get for it – motion detectors, rovers, alternative energy stuff, and more.  It’s a great product.

But getting back to our less plastic and non-snapping circuit, BalletBoy immediately recognized that, “It’s got to be a circle!”  The problem was figuring out how to make the circle work.  They all fiddled with it for a while and they almost got it, but I finally showed them how to wrap the foil “wire” around the metal base of the bulb then touch the bottom of the bulb to the top of the battery while keeping the other end of the foil touching the other side of the battery.

After that, the kids experimented with different ways to attach it.  For example, they discovered that is does work if you turn the battery around.  I also gave them more batteries and let them try attaching them all together.  They immediately got that the two sides of the batteries had to touch with opposite ends (positive to negative) and then when I made the connection to the balloons repelling each other, they seemed to get it.

Finally, I showed them how a paperclip can extend the circuit by setting in in between the bulb and the battery (keeping the foil wire touching the end of the battery and wrapped around the base of the bulb).  However other things, like paper, would make the battery stop working.  I sent each kid out to find three things they though would insulate and three things they thought would conduct.  The stuff they found was awesome.  They were much better at picking insulators.  Mushroom probably had the funniest assortment.  He wanted to test chocolate, an Easter Peep, and some honey!  Other kids had Legos, a balloon, and a number of other things.  The conductors were also interesting.  One of our friends thought surely glass would be a conductor.  Mushroom expected rock to work.  BalletBoy brought in a corn holder and we discovered that it would conduct from one end to the other (meaning the metal must be one piece encased inside the plastic).  All the kids were shocked when the stainless steel dinnerware didn’t conduct electricity.  I realize now I should have taken out some silver.  They may have emerged with the idea that forks just don’t do it!  We recorded all these observations in the journals, which worked really well.  I like when our journals can be used for recording observations like that instead of just notes and illustrations.

Science Week 8: Gravity

A couple of resources to start you out for gravity.  First of all, the Let’s Read and Find Out title was Gravity is a Mystery by Franklyn Branley was a bit of a disappointment.  Unlike most of the Let’s Read and Find Out books, I didn’t feel that this one did a very good job at explaining gravity.  I’m not a scientist, so I really invite someone who understands physics better than I do to correct me if I’m wrong, but don’t scientists think they understand gravity reasonably well?  Why one object should attract another is never anything I’ve seen explained fully, but the basic concept makes sense.  However, this book kept insisting that scientists don’t even really know what gravity is.  The fact that gravity causes an attraction, not just to the earth, but also between all objects, was never mentioned in this book.

I much preferred the simpler, but useful book I Fall Down by Vicki Cobb.  I wouldn’t have minded this sparse picture book having a little more information.  However, it did do something very nice by warning the reader that you’ll need a number of household objects around to illustrate the concepts in the book.  I hate when I’m reading a science book that seems like it’s a text and it suddenly tells you to get up and do an experiment out of the blue.  It’s nice in concept, but sometimes I don’t budget our time for it or have the materials ready (even if it’s just a dishcloth or a scale).

My favorite book of resources this week was The Science Book of Gravity.  I’ve really been enjoying this series, which is from the early 90’s.  The experiments are all pretty simple, but focus on fun.  Not everything we’ve done from this series has worked, but most of the experiments have.  This week, I took nearly all our experiments from there.  I didn’t find anything simple for us to use from the Janice VanCleave book about gravity.

We began with an experiment that you absolutely must try, even if physics isn’t your topic this year.  I rank this among the truly excellent home science demonstrations I’ve seen in my life.  Here’s what you do:

  1. Take a small water balloon and fill it with water.  It should be about the size of a clementine or maybe a tangerine.  A grapefruit is too big.
  2. Open the mouth of a regular balloon very wide and have a partner put the water balloon inside the regular one.  Roll up the mouth so that the water balloon is inside.  Both balloons have some give, so it may take some shimmying, but it can be done.
  3. Blow up the regular balloon and tie it.
  4. Now play with it.  The center of the balloon’s gravity isn’t where you expect and it constantly moves, causing the balloon to act in unexpected ways.  Trust me.  We all giggled as we tried to throw and catch it.

Nothing we did topped that, but we did do a few other fun things.  We built a marble run to think about how gravity pulls us downward all the time.  We weighed ourselves.  We made a simple scale and “weighed” objects by hanging them on a rubber band and seeing how much they pulled on the rubber band.  We also dropped a large combination of objects and watched to see if they hit the floor at the same time.  We dropped some of them into modeling clay (though I realize now Play-doh would have worked better) to see what type of object made the biggest dents.

We enjoyed a couple of good videos.  First, the Eureka video on gravity was a good one.  I’ve posted about this series before, so I’ll just link to it.  You can see it here.  We also, of course, enjoyed the Bill Nye episode about gravity.  Finally, did you know there’s a Schoolhouse Rock video about gravity?  Well, now you do!

Finally, we did one last fun experiment.  Using modeling clay (this was really a modeling clay heavy week), we stuck marbles into one corner of a jar lid.  If you place the lid on a slope with the marbles slightly to the upper end of the slope, the jar lid with roll upward.  But it’s not defying gravity!  The marbles are the heaviest things and they need to go down the quickest way.  Anyway, three of our four lids failed because they weren’t flat on the edge, so make sure you have a completely flat rimmed lid for this one.  Below is a picture of the inside of one of the lids that did not work.  Alas.  But you get the idea.