Summer is in full swing, so we hope you’ve been able to get outside! Today, we are going to have fun with three different sandy experiments.
First of all, what is sand? Where do you see sand?
You might think of a sandbox, the beach, or the desert. Sand is really just small pieces of rock that have been broken down over time. The sand you see at the beach may contain little shell pieces as well. Over time, the repeated wear from wind, water, and other elements break rocks and pebbles into smaller and smaller pieces.
Last week, we talked about acid-base reactions when we created fizzing chalk paint.
Review here: Science of chalk
We’re going to use this same principle to create sand volcano eruptions.
YOU WILL NEED:
- A sandy area (beach, sandbox, or store-bought sand)
- Empty plastic bottle
- Water
- Baking soda
- Vinegar
Here’s what to do!
- Fill your plastic bottle about 1/3 full with water. Add about ½ cup of baking soda (your base) and shake it up until it’s well blended.
- Build a volcano shape around your water bottle. Make sure you don’t get sand inside the bottle. You may need to wet the sand in order to shape it into your ideal volcano. The opening of your volcano will be the mouth of the bottle.
- Dump some vinegar into the mouth of your volcano and watch it erupt!
- Experiment: Try using different amounts of baking soda or vinegar. Does more or less make a difference?
Quicksand
One type of sand you hopefully have not had to deal with is quicksand. This is formed when sand or silt becomes mixed with lots of water. When a person or animal steps into quicksand, it can be very difficult to get out.
Create your own “quicksand”
YOU WILL NEED:
- A pan or container
- Cornstarch
- Water
Here’s what to do!
- You can create as much quicksand as you want! Dump equal amounts cornstarch and water into the pan, and then mix it together.
- If the quicksand seems too dry, add a little water. If it’s way too runny, add a little cornstarch.
- Put your hand in the “quicksand” and try to pull it out quickly. What happens? You’re stuck! Try it again, but slower. What do you notice? When you move slowly, it’s easier to remove yourself from the quicksand. This mimics what quicksand is like. The best way to get out of quicksand is to avoid panic and move slowly.
Sandy Slime
Who doesn’t love a little slime? Use this classic slime recipe and mix in sand for a beach-themed mess!
Before we get messy, let’s review the science behind this particular type of slime.
The slime we are going to create today is a substance called a polymer. A polymer is a large molecule formed from lots of smaller molecules. These smaller molecules, called monomers, form a long chain.
Poly = many
Mono = one
Mer = parts
A polymer has many parts, a monomer has one part. Lots of monomers together form a polymer!
Think of the monomers as beads, and the polymer as a necklace made by stringing the beads together.
Where do we see polymers in our daily lives?
Polymers appear in many products that you see all the time, such as plastic or rubber. Another common polymer is the DNA in your body! DNA is a chain present in all the cells of your body, and it’s what makes you uniquely different from everyone else!
In our slime recipe, one of the main ingredients is glue, which is actually a liquid polymer. The molecules of glue are in separate little strands before you add anything to it. Once you add the special ingredient (laundry starch) to the glue, it acts as a binding agent that links all the little strands together to create a more solid polymer, or in other words... SLIME.
What’s happening when you add liquid starch to glue? Glue is already a polymer, but it isn’t a very strong one. Cross-linking occurs when you add a binding agent to a weak polymer to make it stronger (see the image below). The once weak individual polymer strands are made sturdier because they are cross-linked by the binding agent!
YOU WILL NEED:
(You can purchase our basic slime kit here: Polymer Science Kit)
- White liquid school glue
- Liquid laundry starch
- Water
- Sand
- Bowls
- Measuring cups
Here’s what to do!
1. Measure ½ cup of the clear craft glue and dump it into the mixing bowl.
2. Pour ½ cup of water into the mixing bowl and use the spoon to stir the water into the glue until it looks smooth and well-blended. Write down your observations so far. How does adding water to the glue change it?
3. Mix in your sand! Add a few tablespoons or so and stir it up.
4. Add ½ cup of liquid starch to the mixing bowl and stir it in. How does the consistency of the glue change once you add the starch? Record your observations.
5. Once you stir the starch in, pick up your slime and play with it! What does it feel like? Look like? Is this what you expected to happen?
Happy experimenting!
Sepp, S. 2011. Close-up of sand from the Gobi Desert, Mongolia. Used in accordance with the Creative Commons Attribution Share-Alike 3.0 Unported License. Uploaded from wikimedia commons on 6/11/2018. No changes were made.
Dunn, A. 2005. Quicksand and a warning about it at a gravel quarry in England. Used in accordance with the Creative Commons Attribution Share-Alike 2.0 License. Uploaded from wikimedia commons on 6/11/2018. No changes were made.
Cross-linking. Created by Dr. Erin Nyren.
Slime photo taken by Maddie Van Beek.
Resources:
https://www.education.com/activity/article/Quick_Sand/
https://littlebinsforlittlehands.com/best-sandbox-volcano-eruption/
https://littlebinsforlittlehands.com/homemade-sand-slime-recipe/
https://wiki.kidzsearch.com/wiki/Quicksand
https://www.livescience.com/34748-what-is-sand-beach-sand.html