Thursday, October 30, 2014 - 10:27

We have a special treat for you this week as we get ready to enjoy Halloween…a blog just for kids!! (If you are an adult please keep reading as kids are going to need your help with some of the stuff mentioned below)

Even though the people that work at STEM Fuse are all adults, we certainly don’t always act like it. Today, we’re giving you a list of fun and exciting science experiments that you can do at home. It’s important that you talk to your parents before doing any of the experiments below, as you’ll want to have someone there to clean up the mess you make. They may need to buy some supplies for you too. Afterall, it’s the parents’ job to clean up and buy stuff, right??

Below each experiment is an explanation of how it works. These explanations will help you better understand science and hopefully give you inspiration to create your own fun experiment! When you do create your own experiment – please send us a note and tell us about it - it could be featured on our blog!

Witches Brew – an easy and fun way to make a total mess

What you’ll need:

  • Some sort of large glass bowl or cooking pot, if you can find a dark-colored one, even better.
  • White vinegar
  • Baking soda (make sure it’s not baking powder)
  • Green food coloring (optional)
  • Sunglasses or safety goggles


  1. Pour one cup of baking soda into the witch’s cauldron (your bowl or pot)
  2. Put on your sunglasses or goggles to protect your eyeballs
  3. SLOWLY begin to pour vinegar over the top of the baking soda
  4. Enjoy the bubbles!!!
  5. Keep adding baking soda and vinegar as long as you want – as long as you keep adding, it will keep bubbling!
  6. For extra fun, add some green food coloring!
  7. With an adult’s permission – take a photo of your brew and email it to - we’ll post it on Facebook and Twitter!!

DO NOT eat or drink this mixture. Trust us, it’s GROSS!!

How does this work?

The baking soda (sodium bicarbonate) is a base while the vinegar (acetic acid) is an acid. When they react together they form carbonic acid which is very unstable, it instantly breaks apart into water and carbon dioxide, which creates all the fizzing as it escapes the solution.


Fake Snot – an exceptional way to gross out your siblings

What you'll need:

  • Boiling water (this is where you’ll need an adult)
  • A cup
  • Green Gelatin
  • Corn syrup
  • A teaspoon
  • A quarter cup measuring cup
  • A fork


  1. Let a cup of water boil (have an adult help you)
  2. Put half a cup with that boiling water into a glass bowl (keep the adult around to help)
  3. Add three teaspoons of gelatin to the water
  4. Let it soften before stirring with a fork
  5. Add a quarter of a cup of corn syrup to the water/gelatin mix
  6. Stir the mixture again with your fork and look at the long strands of gunk that have formed
  7. As the mixture cools slowly add more water, small amounts at a time
  8. Gross out siblings, adults and friends as necessary
  9. With an adult’s permission – take a photo of your brew and email it to - we’ll post it on Facebook and Twitter!!

How does this work?

Mucus is made mostly of sugars and protein. Although different than the ones found in the real thing, this is exactly what you used to make your fake snot. The long, fine strings you could see inside your fake snot when you moved it around are protein strands. These protein strands make snot sticky and capable of stretching.



What you’ll need:

  • Large bottle of Diet Coke, like a 2 liter
  • About half a pack of Mentos (they’re a candy…ask an adult to buy a pack)
  • A tube to fit around the top of the bottle, like a 12 inch piece of PVC pipe, or a tall funnel would work too (either one is optional, but helps)


  1. Make sure you are doing this experiment in a place where you won't get in trouble for getting Diet Coke everywhere…and we do mean EVERYWHERE. Outside in the grass is a good place.
  2. Stand the Diet Coke upright on a flat surface – might want to use a plate or something to keep it standing upright.
  3. Unscrew the lid.
  4. Put your funnel or tube on top of the bottle so you can easily drop the Mentos in all at the same time (about half the pack is a good amount).
  5. Time for the fun part, drop the Mentos into the Diet Coke and back away!!

If you've done it properly a huge geyser of Diet Coke should come flying out of the bottle, it's a very impressive sight. The record is about 29 feet high!

With an adult’s permission – take a photo of your brew and email it to - we’ll post it on Facebook and Twitter!!

How does it work?

Although there are a few different theories around about how this experiment works, the most favored reason is because of the combination of carbon dioxide in the Diet Coke and the little dimples found on Mentos candy pieces.

The thing that makes soda drinks bubbly is the carbon dioxide that is pumped in when they bottle the drink at the factory. It doesn't get released from the liquid until you pour it into a glass and drink it, some also gets released when you open the lid (more if you shake it up beforehand). This means that there is a whole lot of carbon dioxide gas just waiting to escape the liquid in the form of bubbles.

Dropping something into the Diet Coke speeds up this process by both breaking the surface tension of the liquid and also allowing bubbles to form on the surface area of the Mentos. Mentos candy pieces are covered in tiny dimples (a bit like a golf ball), which dramatically increases the surface area and allows a huge amount of bubbles to form.

The experiment works better with Diet Coke than other sodas due to its slightly different ingredients and the fact that it isn't so sticky. Diet Coke that had been bottled more recently worked better than older bottles that might have lost some of their fizz sitting on shop shelves for too long, just check the bottle for the date.


The Mysterious Floating Ketchup Packet – wow your family and friends

What You'll Need

  • A 1 liter plastic bottle
  • Ketchup packet from a fast food restaurant
  • A tablespoon
  • Salt (using Kosher salt helps keep the water from becoming foggy, but table salt is fine too)


  1. Remove any labels from the bottle and fill it all the way to the top with water.
  2. Add a ketchup packet to the bottle.
  3. If the ketchup floats, you're all set - go to step 5.
  4. If the ketchup sinks in the bottle, go to step 6.
  5. For the floating ketchup packet - simply screw the cap on the bottle and squeeze the sides of the bottle hard. If the ketchup packet sinks when you squeeze it, and floats when you release it, congratulations, you're ready to show it off to amazed friends and family. If it does not sink when you squeeze it, try a different kind of ketchup pack or try a mustard or soy
  6. If the ketchup packet sinks immediately when added to the bottle, add about 3 tablespoons (45 ml) of salt to the bottle. Cap it and shake it up until the salt dissolves. (Kosher salt will keep the water from getting too cloudy, although it will usually clear up over time if using regular table salt.)
  7. Continue adding salt, a few tablespoons at a time until the ketchup packet is just barely floating to the top of the bottle.
  8. Once it is consistently floating, make sure the bottle is filled to the top with water, and then cap it tightly.
  9. Now squeeze the bottle. The magic ketchup should sink when you squeeze the bottle and float up when you release it. With some practice you can get it to stop in the middle of the
  10. You’re a magician!! Go wow your friends and family. We think grandparents will like this one a lot. If you put on a show – send us a picture or a video!

How does this work?

This experiment is all about buoyancy and density. Buoyancy describes whether objects float or sink. This usually describes how things float in liquids, but it can also describe how things float or sink in and various gasses.

Density deals with the amount of mass an object has. Adding salt to the water adjusted the water's density to get the ketchup to float. Sound complicated? It is, but here's the basics on the ketchup demo...there is a little bubble inside of the ketchup packet. As we know bubbles float, and the bubble in the ketchup sometimes keeps the heavy packet from sinking. When you squeeze the bottle hard enough, you put pressure on the packet. That causes the bubble to get smaller and the entire packet to become MORE DENSE than the water around it and the packet sinks. When you release the pressure, the bubble expands, making the packet less dense (and more buoyant) and, alas, it floats back up. This demonstration is sometimes known as a CARTESIAN DIVER.


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