This is a recording of a recent live teleclass I did with thousands of kids from all over the world. I’ve included it here so you can participate and learn, too! (Click here if you’re looking for the more recent version that also includes Chemical Engineering.)
When you think of slime, do you imagine slugs, snails, and puppy kisses? Or does the science fiction film The Blob come to mind? Any way you picture it, slime is definitely slippery, slithery, and just plain icky — and a perfect forum for learning real science. But which ingredients work in making a truly slimy concoction, and why do they work? Let’s take a closer look…
Materials:
- Click to download worksheet
- Sodium tetraborate (also called “Borax” – it’s a laundry whitener) – about 2 tablespoons
- Clear glue or white glue (clear works better if you can find it) – about 1/2 cup
- Yellow highlighter
- Pliers or sharp razor (with adult help). (PREPARE: Use this to get the end off your highlighter before class starts so you can extract the ink-soaked felt inside. Leave the felt inside highlighter with the end loosely on (so it doesn’t dry out))
- Resuable Instant Hand Warmer that contains sodium acetate (Brand Name: EZ Hand Warmer) – you’ll need two of these
- Scissors
- Glass half full of COLD water (PREPARE: put this in the fridge overnight)
- Mixing bowl full of ice (PREPARE: leave in freezer)
- Salt
- Disposable aluminum pie place or foil-wrapped paper plate
- Disposable cups for solutions (4-6)
- Popsicle sticks for mixing (4-6)
- Rubber gloves for your hands
- Optional: If you want to see your experiments glow in the dark, you’ll need a fluorescent UV black light (about $10 from the pet store – look in cleaning supplies under “Urine-Off” for a fluorescent UV light). UV flashlights and UV LEDs will not work.
When they are heated past the melting point and subsequently allowed to cool, the aqueous solution of sodium acetate and water becomes supersaturated. This solution is capable of cooling to room temperature without forming crystals. But if you touch a crystal to the solution, it will start a chain reaction.
Notice that you can take your “icicle” and change it back into liquid by heating it above the melting point again. When it cools, it will go back to room temperature without crystalizing.
Why does the liquid have to heat up to become an ice?
Yes, it’s the first item listed in the material list. Click on the link that says “Click to download worksheet”.
Is there a work handout the kids can fill out as they view the lesson?
Yes, it’s the first item listed in the material list above. Do you see it?
Is there a worksheet for this teleclass on chemistry for 2nd grade?
I’ll have Tonya connect with you. The program isn’t available by grade, so we have to manually unlock the grade you’re looking for.
I can’t seem to open the video link which I think is part of second-grade science.
I’ll have Tonya connect with you personally – it sounds like something is wrong with your account since you can leave comments but can’t access the videos. Sorry for the trouble – we’ll get it fixed!
Where is the video?