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Two Fun Water Experiments from "Pop Bottle Science" Kids Can Try at Home

Join us the in CAMP Science Lab for two experiments that really make a splash!

Sarah Burns

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Life is filled with questions: Why is the sky blue? How do bugs walk on top of water? What keeps metal boats from sinking? These are all great questions that can all be answered with the help of SCIENCE! Pop Bottle Science is a nifty kit that can help kids discover the answers to these questions and over 70 more, with simple, hands-on learning experiences designed to explain complex science concepts, and unlock the mysteries of the world around us.

We can’t answer every single question life throws at us, but hey, since we’re here, let’s go ahead and tackle 2 out of the 3 Big Sciencey Questions above, starting with…

1. How Do Bugs Walk On Top Of Water?

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It looks like magic — the way water bugs can just go for a watery stroll without sinking, or making a splash. But it’s not magic, and you can demonstrate the same principles at home with stuff you probably already have around the house!

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What You Need:

  • A container filled three-fourths of the way with water

    Ground pepper

    Liquid soap

Do This:

  • Put on your imagination caps, and set them to “pretend” mode: Let’s pretend the pieces of ground pepper are actually little bugs!

    Sprinkle the ground pepper over the water.

    Look very closely at the ground pepper, and how it interacts with the water’s surface: you should see a small indent or dimple around the pieces of ground pepper

What’s happening?

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That dimple you’re seeing is the result of surface tension. Surface tension acts like a thin skin over the surface of the water, so when you see bugs “walking on water," what they’re actually walking on is the water’s surface tension! Now let’s see what happens when that surface tension is disrupted…

Do This:

  • Put a tiny dab of liquid soap on the tip of your finger, and touch it to the surface of the water.

What's Happening?

pepperscattering

When the soap meets the water, it breaks the surface tension, scattering the pepper away from the soap, and even sinking some of the larger pieces. 

So the next time you see bugs going for a walk on top of water, remember, it’s actually surface tension they’re walking on – and don’t spoil their walk with any soap, okay?

Watch the Whole Experiment Here:

2. What Keeps Metal Boats from Sinking?

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Boats are metal, and metal is obviously too heavy to float, right? Well, not exactly. Here’s an easy experiment that demonstrates what you need to know to avoid that sinking feeling.

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What You Need:

  • A container filled three-fourths of the way with water

    A 12x12 inch square of aluminum foil

    A handful of pennies

Do This:

  • Drop a penny into the container: What happened to the penny? Did it float?

What's Happening?

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Definitely not floating.

Of course it didn’t float — if coins could float, no one would toss them into wishing wells! 

Do This:

  • Take the foil, and fold all four corners to the center. And again. Gently shape this square into a small boat with high sides. You’re not being tested on your boat-building skills; just aim for an egg shape.

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A seaworthy vessel.

  • Now, place your foil boat in the water.

What’s Happening?

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Sailing the high seas.

The boat floats! But the boat is made from metal, and the penny was made of metal, so what gives? It’s because the foil is lighter right? That’s gotta be it. So let’s go ahead and ...

Do This:

  • Gently drop a penny into the boat. Does it still float? Try another penny or two ...still afloat?

What’s Happening?

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Unsinkable!

The boat is still floating! That’s because the boat's size, weight and shape make it buoyant. When something has buoyancy, it’s able to float, and even carry cargo! 

Do This:

  • Grab some more pennies. A whole bunch, like whatever you can scrounge up from under the couch cushions, and underneath the seats in the car. Now drop all those pennies into the boat. 

What’s Happening?

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Unsinka — wait a minute...!

Dropping a big load of pennies overwhelms the buoyancy of the boat, and the boat sinks. Buoyancy is a powerful force, but it has its limits. 

Watch the Whole Experiment Here:

You have more questions, and we have more science! Try Pop Bottle Science for these and many more experiments to learn more about how the world works!