Make Your Own Magnetic Molecular Model Kit

In this post, I will show you how to convert an old molecular model kit into a futuristic magnetic molecular model kit.  Why would one want to take the time to add magnets to a molecular model kit?  Let me answer that before I explain the steps.  By the way, don’t worry, it’s not as hard or time-consuming as you might think. 

One of the most fundamental and often misunderstood concepts in chemistry is bond energy.  For some reason, students have a difficult time remembering that when bonds form they release energy and to break bonds energy must be added.  Maybe it’s because they think of an explosion as a way of breaking something and explosions release energy.  Maybe it’s because they are told in biology that when ATP breaks off a phosphate ion to become ADP energy is released.  Maybe it’s because we teach students the misconception that bonds contain energy.  If a bond contains energy, doesn’t make sense to think that when a bond is broken it would release the energy it contains?

To help my students understand and to “see/feel” this concept, I use magnets as a model for chemical bonding.  In the past, I used a couple of magnets as atoms and demonstrated that when the magnets come together energy is released, i.e. the magnets moved and made a "smack" sound when they came together.  I also pointed out that when I needed the magnets apart I had to use my energy to pull them apart.  I thought it was a good demonstration and I’m sure most of you have used it in your classes. 

While I liked my demonstration, I always felt it was missing something that would give it a bigger impact.  I wish I could take all the credit, but I was inspired by Derek Muller, the host of Veritasium.  He created Snatoms, which was recently funded on Kickstarter.  In his video for Snatoms, he does a great job of explaining why the magnetic model kit is superior to the old ball-and-stick kits that have been used in chemistry for ages.  For one, bonds are not sticks but a force that holds atoms together.  Second, they are very tactile; you can actually feel the “chemical bond”.  Using the magnetic model kit, students will feel the energy they must add when they break the bonds and they will feel the energy when the atoms are pulled from their hands as the bond forms.  I really love Derek’s Snatoms but I have two problems with them.  One, they are not available yet.  Second, they are a little pricey.  During the Kickstarter campaign, you could buy the basic set of 6 carbon, 6 oxygen and 12 hydrogen Snatoms for $49 plus shipping.  (Note: I loved his idea so much that I backed his project at $89.)  I don’t know what the retail cost for Snatoms will be, but I know what I’m about to show you will cost much less!  I built my magnetic kit for less than $22.  Please, if you have the money buy Derek’s Snatoms.  

How to make your own magnetic model kit

Here's how to easily convert an old ball-and-stick molecular model kit into a state-of-the-art magnetic kit that will impress your colleagues and students.  First of all, you will need the following supplies:

• Old ball-and-stick model kit (I used an old Sargent-Welch wooden kit I found in the storage room.  Any model kit will work.  The atoms in my kit are 1.25 inches in diameter.  You may have to adjust the size of the magnets if your atoms are a different size.)
• Magnets (I used magnets N42 epoxy neodymium magnets from K&J magnets)
• Glue (I used white Gorilla Super Glue)

That’s it!  That’s all you need.  I used the N42 epoxy neodymium magnets because the magnets happen to fit into the holes of the atoms that came in my model kit and they are strong enough to hold the atoms together.  

Now, all you have to do is glue the magnets to the atoms.  It's that easy.  Well, sort of...  THIS IS IMPORTANT, SO DON'T SKIP THIS PART!  I quickly realized that you need to pay attention to the polarity of the magnets as you attach them.  If you glue all the magnets in the same direction then the atoms will all repel each other.  Just make sure that you alternate each magnet.  For example, I started with some hydrogen atoms.  On the first hydrogen atom I glued a magnet and on the second hydrogen, I glued the magnet in the opposite direction of the first.  For oxygen, I did the same thing, but I made sure that the two holes in the oxygen atom had magnets with opposite poles facing out.  I repeated this pattern for carbon making sure that I had two similar magnetic poles facing out at each hole in the carbon atom.

Cost

Your cost will depend greatly on whether you can find an old kit in your science storage room.  I only made one set to use for demonstrations so I didn't need to magnetize all the atoms in the kit.  Here is a breakdown of my cost for the supplies:

• Old Model Kit = Free
• 50 Magnets ($0.34 each) = $17.00 + $5.00 for shipping; total cost = $22.00 for magnets
• 12 hydrogen atoms (1 magnet each) = 12 magnets
• 5 carbon atoms (4 magnets each) = 20 magnets
• 6 oxygen atoms (2 magnets each) = 12 magnets
• 2 nitrogen atoms (3 magnets each) = 6 magnets
• Gorilla glue = $5.79
• Grand total = $27.79

If you don't have a molecular model kit to use then it may cost you about $20-25 more.  You can find them on Amazon and through many science supply companies.  You could also use wooden spheres from a local craft store.  I wouldn't recommend using styrofoam balls, I think the magnets are too strong.

Modifications

The magnets I used fit perfectly into the holes that were predrilled into the atoms.  It was pure luck that the magnets fit so well.  I was planning on just gluing the magnets directly to the surface of the atoms.  You may have to do this if your magnets don't fit into the holes.  I suppose you could drill out the holes to fit the magnets, but that just seems like too much work to me.  

Now, you have a magnet molecular model kit that will help your students better understand the concept of bond energy.  If you have the time and the resources feel free to make sets for your entire class.  I wouldn't recommend you do this your first time through.  You will be overwhelmed and have atoms and magnets glued to your face!  Remember keep it simple.  The goal is to teach students that bonds are forces, not sticks and that bonds formed release energy and energy must be added to break bonds!

Please, share your thoughts and experience in the comments below.  Let me know if you have any ideas on how to lower the cost.

Thanks,

Dan
www.payefg.com
@ddulek