Not your usual experiment, this is a book: “The League of Scientists” is a young adult fiction book by Andy Kaiser (the creator of Digital Bits Science Lab).

Equipment needed:

The League of Scientists is available here: http://www.LeagueOfScientists.com

The Digital Bits Science Lab Experiment:

The League of Scientists is a group of smart kids who love science. They use their knowledge and critical thinking skills to solve seemingly-supernatural mysteries.

One of the components of the book is the mystery aspect, and not just the “main” mystery. In most chapters, there is a puzzle. The solution to the puzzle involves the application of science or critical thinking. The book is intended to give science education (and scientific applications – something you don’t always get from such fiction) while still giving kids a good story and characters.

Learn about buoyancy. This lab answers the question: Why is it easier to swim in the ocean than in a lake?

Equipment needed:

An egg (it can be either raw or hard-boiled. It needs to be fresh.)

A tall, wide glass

Water

A long-handled spoon for stirring in the glass

Salt (you’ll need a lot of salt, more than what’s contained in a salt shaker. If you’re purchasing for a group or class, shop for salt in bulk.)

The Digital Bits Science Lab Experiment:

Carefully place your egg in the empty glass. Then fill the glass with water, leaving an inch or so of space at the top. You’ll see that the egg sinks, and rests happily at the bottom of the glass. (If your egg floats in the fresh water, that’s an indicator of an old egg. Use a fresh egg instead.)

Now that we’ve seen the egg sink, use the spoon to carefully lift the egg out of the glass.

Next, pour salt into the water.

Keep pouring.

And pour a little more.

Stir it.

The goal is to get so much salt in the water, that you can’t dissolve any more. Stir the mixture for a while. If you lift the spoon out after stirring, and still see a few salt grains clinging to it, your salt-water mixture is ready.

Using the spoon, carefully lower the egg into the water. If you’ve mixed enough salt in the water, the egg will now float!

The egg floats in the salt water because it has more buoyancy in salt water than in fresh water. Buoyancy is determined by the density of the water. Fresh water is not very dense. Things will sink easier in fresh water. Salt water consists of water mixed with a LOT of salt. That salt adds density to the water. So when you put the egg in salt water, the heavier density of the water causes the egg to float.

This is why it’s easier to swim in the ocean than in a lake: the ocean is salt water, a freshwater lake is not. Your body is more buoyant in the higher-density salt water, and you can more easily float.

Learn about buoyancy. Be able to answer the question: “How does a boat float?”

Equipment needed:

Play-Doh or some sort of modeling clay.

The Digital Bits Science Lab Experiment:

Roll your Play-Doh or modeling clay into a ball:

Drop it into water. You’ll see it sink:

Next, take another handful of Play-Doh – use the same amount as before. Make a deep boat-like or cup shape, something similar to what you see here:

And put it in the water:

Why does our boat float? This experiment demonstrates the concept of buoyancy. Also called the “Archimedes principle“, this is what happens when a boat is placed in water: The water pushes back! The Archimedes principle tells us that an object in liquid is pushed upward by a weight equal to the amount of water the object displaced.

To put it simply: When you put your boat in water, how much water does the boat “push” out of the way? Take that water, and weigh it. That weight is the same weight pushing the boat “up” out of the water.

So in this case, the weight of our displaced water (the amount pushed out of the way) was more than the weight of the Play-Doh boat. That’s why our boat floats!

Note that the experiment above was done with Play-Doh. And a word of warning – this experiment is messy! Play-Doh (and I would assume other modeling clays) is water-soluable, unless you mold and harden the clay before dunking it. So the longer you leave the Play-Doh in the water, the more it will turn into a gooey, sticky mess. Parents and teachers, you’ve been warned. Kids, you’ll love it!