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Elf on the Science Shelf – Hot Chocolate and Screaming Balloon

1525714_10152204281243804_2006007263_nThis is the first in a series of posts featuring science activities for your Elf on the Shelf. You can see the whole series here.

The Elf on the Shelf goes way back in my family. My Mom had an elf when she grew up in the late 1940s – 50s – an original elf on the shelf. He sat in one spot all of December keeping an eye on everyone.

When my first son was born in 2005 she bought a stuffed elf for our family just before the whole Elf on the Shelf phenomenon exploded. So our elf doesn’t look like everyone else’s elf, which luckily my kids don’t mind. You see, our elf is the Head Elf! It says so on his shirt. This means that he is busy supervising all the other shelf elves and doesn’t have time for all the shenanigans that the others get into.

But that doesn’t mean I don’t feel the pain of my fellow mother’s whose enthusiasm for a new holiday tradition early on has made them a slave to the elf. For many thinking of new and original escapades for your elf, year after year, is worth the “He’s watching!” good behavior for a few weeks.

So for the next few weeks I will be posting some ideas for your elf that include a little science learning – and hopefully keep your kids busy for a few moments so you can enjoy a cup of coffee in peace.

Hot Chocolate Effect

This experiment is by far the most popular on this web site since I posted it last year. The setup, and the science is pretty easy.

Supplies (if you have more than one kid you may want to include enough sets for everyone)
Ceramic mug
Packet of hot chocolate

Set up the mug, spoon and hot chocolate with the following note next to your elf. Feel free to print out mine, or copy in your own elves handwriting.

Try this experiment with some cocoa. Fill your mug with hot milk and give it a tap. The cup will vibrate which you hear as sound. Pour in your packet of cocoa and give a good stir. Tap on the cup while you wait for it to cool. Do you hear how the sound changes?

When you mix in the cocoa you also add bubbles. This makes the milk less dense to the cup can vibrate faster. Faster vibrations mean a higher sound. As the bubble rise and pop, the milk become more dense again and the sound gets lower.

Screaming Balloon

Here is another sound experiment that will keep the kids busy. They can make noises or just throw the balloon around. The nut inside moves the center of gravity, which causes some unpredictable motion. Hilarity will ensue.

Hex nut

Put the nut inside the balloon before you blow it up and tie off the end. Set the balloon next to your elf with this note. Again, feel free to print out mine, or copy in your own elves handwriting.

While the rest of the elves are busy making toys for the big day I thought you might help by testing one out. This balloon is two toys in one!

Put your hand on the balloon and swirl it around. The hex nut inside will roll around the balloon. The sound that you hear is the 6 pointy corners.. Each time they hit the side of the balloon they start a vibration and vibrations are sound! What do you think would happen if I’d used a penny instead?

Now give the balloon a toss. Watch it wibble wobble as it flies through the air. Can you play catch with this crazy balloon? The hex nut inside doesn’t stay in the middle. It slide around all over the balloon causing it to wibbl,e wobble and bobble as you try to figure out where it will go!