6 Science Projects for Kids on my To-Do List

There are so many cool science projects out there. I am always working to create more fun science projects for kids, but I have been secretly making a little list of science projects I want to do with my own kids! These are my top 6 science projects I want to get around to in 2018 and make into easily accessible and explained mini maker activities.

Top Science Projects for Kids this coming year:

1.  Grow a crystal tree

2. Make slime

3. Check out magnetic cereal

4. See invisibility in action

5. Egg in a bottle

6. Make a Lava Lamp

Learn more about each of these science projects below including why I can’t wait to do them, and the science behind them!

1. Grow a Crystal Tree

Chemistry in action: In this activity, you use blotter paper and a mixture of ammonia, salt, bluing, and flat cardboard.

Why I can’t wait to do it: I am always a big fan of mixing art and science, I am a true believer that they go hand in hand. I love that you can color the crystals using markers on the edges of the trees, and also see the crystal growth happen over the course of an hour.

The science behind the science project: There are a few processes in action here. First, there is the physics of capillary action pulling the ammonia mixture up the cardboard or blotter paper. Capillary action happens when liquids find themselves in tight spaces, places like in a paintbrush, a thin glass tube, paper towels, or in porous materials like clay. The liquid adheres to the walls or cells of the container through intermolecular forces. These forces can beat out gravity and even act to propel the liquid up.

Once the liquid has saturated the tree cutout it will begin evaporating from all of the edges. As it evaporates the capillary action will continue to pull up liquid from the base. The evaporation of ammonia and water causes a build-up of salt at the cut edges of the cardboard.

Why do you need ammonia if you are creating salt crystals? The ammonia helps speed up the evaporation process, without the ammonia it would take days for the tree to form crystals. In fact, if you are hoping for faster crystal growth you can add more ammonia to the mixture.

Why do you need laundry bluing agent? The laundry bluing agent might seem like an odd addition to this chemistry project, but it plays a key role in the crystal look. Salt crystals will still form without the bluing agent but they would look much more like the thick chunky salt crystals we see in our kosher salt. Laundry bluing is made of very small particles that do not dissolve – imagine tons of tiny little balls floating around in the solution. This is called a colloidal solution (did you know milk is a colloidal suspension of fat globules and water?!?). These tiny little balls suspended in the solution act as millions of tiny seeds for crystal growth and allows your tree to create a fine broccoli like texture!

Other cool science projects related to this one are crystal geode growth and cooking up rock candy – the later of which is going to be in our winter STEM activities!

2. Make Slime

Physics in action: In this activity, you use household ingredients like borax and glue to create liquids that behave in a funny manner.

Why I can’t wait to do it: Somehow I’ve been doing a ton of science projects with my kids and have yet to ever make slime. I’m not even sure we have played with cornstarch and water – one of my favorite non-newtonian liquids that gets hard when you slap it. I’m pretty sure we are missing out, and I feel like I need to remedy it ASAP.

The science behind the science project: Slimes are non-Newtonian fluids – that is a fancy way of saying the viscosity (kinda of like the thickness) changes when something is mixed, squeezed, stressed, or vibrated instead of just through temperature.

There are lots of different ways to make slime, and lots of them behave differently. For example, slime created with Elmer’s glue will get thinner as you mix it or pull it apart. This is because Elmers glue thins with shear forces. Slime created with borax, however, is the opposite. Mixtures of borax get thicker with shear stress (like stirring or pulling).

How does mixing or pulling change the viscosity of your slime? The materials you use in slime are made of polymers. Polymers are like long strands of molecules chained together. These polymers are so long that they often wind up and knot themselves up, sometimes even bonding with other nearby polymers.

When you mix up a polymer that thickens with the mixing action you are basically straightening out the polymers and tangling them up with each other making the slime more viscous. When you stop stirring or pulling the polymers slowly go back to their original states and naturally untangle, making the slime softer and less viscous. For slimes that get softer when you mix them it is because you are breaking apart globs of polymers that have bonded together (did you know you were strong enough to break hydrogen bonds?!?). This lets them move more freely and allows the slime to flow better. When you stop mixing the bonds reform and the slime gets thicker!

How does borax-glue slime form? The long polymers from the white glue crosslink with each other because of the added ions from the borax!

3. Check out magnetic cereal

Physics in action: In this science project you will have the chance to see magnetism in action and find out why iron is so important to our bodies. All you need is cereal, a blender, and a strong magnet like this one.

Why I can’t wait to do it: I think we often don’t think about what is in our food or why we put certain ingredients, like iron, in our diets. I also think it gives a great wow factor to see metal in your food!

The science behind the science project: The US and many other countries fortify their foods with vitamins and minerals to help the health of the greater population. One of these added items is iron.

Iron is added to fortified foods to help address nutritional anemia and improves mental health, cognitive development, and productivity. Our blood needs iron to be able to carry oxygen from our lungs to the rest of our body, which means we need iron to function properly.

We fortify our foods because it ensures all of our population has access to these supplements despite their nutritional preferences (that is, we don’t have to think about people changing their habits since we fortify commonly eaten foods like flour and cereals).

The added iron is found as very tiny iron flakes, but it is still the same iron you would find in iron nails. Iron is iron after all. Iron is a metal that can be magnetized and thus with a strong magnet and blended up cereal you can actually attract all those tiny iron flecks and move them around!

How is iron a magnet? It isn’t. Iron is a magnetizable metal. You’ll notice that an iron nail won’t naturally stick to your fridge like other magnets do. However, when you put a strong magnet next to iron it becomes magnetized and attracted to the strong magnet!

How is the iron added to breakfast cereal? First iron is ground into very small flakes. These flakes can then be either added to flour or cornmeal used to make the cereal, or it can be sprayed on the flakes just as sugar is sprayed on frosted flakes!

4. See invisibility in action

Physics in action: This is one of the coolest science projects when it comes to the physics of light and helps kids learn about the index of refraction. All you need is pyrex and oil!

Why I can’t wait to do it: My seven-year-old is huge into the Harry Potter series right now and gasped when he was gifted an invisibility cloak at Christmas his first year. While something like that doesn’t exist for us, it does exist for glass, which is pretty cool. Plus, you don’t need much for this experiment, just oil and glass – although I will likely do it with a layer of water in the outside jar, and also show it with a pencil.

The science behind the science project: The speed of light changes when it enters different mediums or substances. Think of light as a really, really fast runner. In air, it can run faster than when it is in molasses, because the molasses is thicker (or more viscous) than air. The light has to push through it harder and thus is slowed down.

When light hits a surface, like the surface of the glass, some of the like is reflected back at us, while some of the light is refracted through the glass. It is the refracted light in the glass that will slow down. This slow down causes the light to bend at an angle, which is why if you put a straw in water and look at it from the side it looks a bit funny.

Oil and pyrex glass, however, have the same index of refraction, that is, light slows down by the same amount in the pyrex glass as it does in the oil. Because of that, the interface between the pyrex glass and the oil can’t be seen very well and the glass disappears.

What about the edges? You can still see the outline of the pyrex glass when it is immersed in the oil. Why? There are impurities in the pyrex that change the index of refraction ever so slightly throughout the piece. On the edges, these small changes are compounded by the fact that you aren’t looking through a thin piece of pyrex but a thick piece.

5. Egg in a Bottle

Thermodynamics in action: In this science project kids get to see the effect that temperature has on pressure as they suck an egg into a bottle.

Why I can’t wait to do it: I remember being in preschool decades ago and seeing my dad do this experiment with the class. I remember being so astonished and shocked and I love giving that same feeling to my kids when we do science projects together.

The science behind the science project: This is a great way to show the effect and power that gasses can have on ordinary objects. The bottle is filled with a gas, the same gas that we breathe every day, air. When air (and other gasses) get hot they expand, that is, they take up more space. This is because hot molecules move around faster than cold molecules.

But if the bottle was filled with air, how can it expand? That is a great question! The bottle does indeed start off filled with air, and it looks like it is closed because of the hard-boiled egg resting on top. However, that egg doesn’t create a seal around the bottle and the expanding hot air can escape around the edges of the egg. Remember, molecules are very tiny and can fit through lots of small spaces.

Now that hot air has escaped and the match has burned through all the oxygen in the bottle the fire will go out. From here the air begins to cool again. That means the air takes up less space. Since some of the hot air has escaped the bottle there is now not enough air to fill the bottle. This creates a high pressure on the inside of the bottle, and a pressure acting over an area is a force (the area is the egg in the bottle). This pressure will pull the soft egg into the bottle!

It is so much fun to remember my own personal response to this and other science projects from preschool that I really can’t wait to share it with my kids, especially now that I know how to fully explain the physics and thermodynamics behind it (yay PhD!)!

6. Make a Lava Lamp

Chemistry in action: Kids will learn about polarity and density of liquids in this science project. You’ll need water, oil, coloring (oil and water based colors would be cool), and alkaseltzer.

Why I can’t wait to do it: My three-year-old loved the dancing corn science project in our Thanksgiving STEM series and I know she will absolutely love to ogle over this one too. Also, my seven-year-old made a density column last year in our Pirate’s Treasure Buoyancy unit and I think it would be great to revisit the science of it.

The science behind the science project: Oil and water don’t mix, even if you try really hard, or mix them for a really long time they will eventually separate out from each other. Why? Because water is polar and oil is non-polar. That is water is slightly negative on the top, and slightly positive on the bottom, while oil has no charges hanging out anywhere. Since like charges attract each other water forms a network of water molecules bonded together. This bonding is called hydrogen bonding. As they bond together they naturally move and non-polar items or liquids out. This creates a bubble of water and a bubble of oil.

Why does the oil sit on top of the water? This is because of the density of oil versus the density of water. Density is the mass per unit volume, and in liquids things with a larger density sink to the bottom. A cup of water weighs more than a cup of oil, which is why the water sinks to the bottom while the oil stays on top.

Why do you need Alka-Seltzer? Without the Alka-Seltzer, the water would just rest at the bottom of the oil. The gas bubbles from the Alka-Seltzer propel bubbles of water up into the oil, which then sink back down to the bottom by the force of gravity.

I definitely think my kids will love this science project, but I do have one little add I am planning on. In the projects, I have seen you add coloring to the water, likely because most food colorings are water-based, and thus dissolve in the water piece and not in the oil. There are, however, oil-based colorings, and I think it would be cool to have one color for the water and another color for the oil.

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