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.

A simple experiment with a piece of paper shows an interesting aspect of how air pressure works.

Equipment needed:

Paper (Standard letter-size paper will work fine, though heavier paper stock like resume paper or construction paper will work better.)

The Digital Bits Science Lab Experiment:

Fold the piece of paper in half. Then place it on the very edge of a table, so that the paper “tunnel” points off the edge of the table:

Next, stick your face down near the opening to the paper tunnel. Blow a steady stream of air through the tunnel. Try to aim so you’re blowing down by the table surface, in the center of the paper (indicated by the blue arrow).

The paper will bend down towards the table! If the paper is stiff, it’ll bounce back up when you stop blowing. If the paper is flimsy (like regular printer or writing paper), then it’ll flatten down to touch the table surface, and will stay there.

What’s happening here? When you blow air through the paper tunnel, you’re changing the air pressure inside the tunnel. The air pressure between the inside and outside of the tunnel was previously the same. But when you blow air, the air pressure inside the tunnel drops – it’s now lower than the outside air pressure. The outside pressure pushes down on the paper (as indicated by the red arrows), and the paper flattens.

One of the classic fun things to do with a balloon is to “squeak” it. This easy game is the result of some interesting science – air pressure and sound at the molecular level. This is also very similar to the way we use our vocal cords to speak.

Equipment needed:

Balloons

The Digital Bits Science Lab Experiment:

Blow up a balloon. Hold the mouth of the balloon in both hands. Stretch the mouth, pinching your fingers on the balloon while pulling them apart, as in the picture below.

As the air flows out of the balloon, you’ll hear a high-pitched, loud squeaking noise. You can adjust the tension on the balloon mouth, and the pitch and volume of the squeaking will change.

What’s happening here? Why does a balloon squeak when you stretch the mouth?

Stretching the mouth of the balloon makes a very tiny space for the air to flow out of the balloon. The air pressure of the balloon itself forces the air out the mouth, but because of the stretching, that space is limited. The airflow causes the balloon mouth (the stretched part) to vibrate. The vibration makes the noise.

Put your hand on your upper neck – right under your jaw – and hum. You’ll be able to feel a vibration, similar to the vibration at the mouth of the balloon. This is air being forced over your tightly-stretched vocal cords. Remember how tightening or loosening the balloon mouth changed the sound of the squeaking? Hum in a high pitch and feel your neck. Hum in a low pitch, and the vibration will change.

You talk using a similar method to the way the balloon squeaks. But the balloon experiment is a simple demonstration, capable of just a few annoying noises. Your body is a highly-developed machine. You can make noises a lot more impressive than any balloon.

This is a fun experiment showing an interesting limitation of the human body: follow the instructions below, and try to open your fingers to simply drop an object. You won’t be able to do it!

Equipment needed:

A pair of hands (yours will work fine)

A friend

A small, flat object (a coin or bottlecap will work fine)

The Digital Bits Science Lab Experiment:

Clasp your hands together, folding all fingers down. Then fold up your ring fingers. Have your friend put the small, flat object between your two ring fingers, like so:

Now, try to separate your ring fingers and drop the object you’re holding.

You can’t.

You may notice you can slide your ring fingers from against each other, but you can’t actually move them apart.

What’s happening here? This is an easy demonstration of some of the limitations of the human body. When your hands are clasped together in that particular way, your tendons are pulled so that your fingers can’t move outward.

Your body is a well-functioning, intricate mechanical device. When you look at a human body, don’t think of it as a single unit. Realize that inside, there are many pieces and parts that work together. And in this experiment, you can put the body in such a position so that some of those parts don’t work!

This “experiment” is a little different than usual. We’ll take a break from the usual Science Lab experiment to give a quick review of Elementeo, a card game that can be used as an educational tool to introduce basic chemistry concepts. It’s one of those rare games with fun gameplay as well as education.

Equipment needed:

An Elementeo board game, available at http://www.elementeo.com

The Digital Bits Science Lab Experiment:

In addition to the comprehensive instruction book, the game contents are what you see here:

As the box says, Elementeo is intended for “Ages 9-99″. It actually works for children even younger, as long as they understand certain basic game-playing aspects. It’s intended for 2-6 players.

The skill level required is also adjustable: there are 5 different game variants. If you want to play the more difficult versions, those versions add complexity to the more simple games.

The core game, a part of each variant, is simple: each team (or each player) has a certain number of “electrons”. Your goal is to bring your opponent’s electron count to zero. The game variants and difficulty give you different ways of doing that. The cards themselves represent mystical, mythical creatures andtechniques fighting it out on a battlefield.

This is primarily a card-playing game, like the collectible card games for “Magic: The Gathering” or “Pokemon“. However, Elementeo isn’t collectable – you’re given everything you need to play all variants of the game.

The cards look like this:

As you read the text on the cards, you’ll see that some is “flavor text” – something funny or interesting to read about the card in question. But the rest of the cards’ contents is information. Some of this information is used to play the game. Some is information about the element or compound in question.

For those who don’t know chemistry, the Elementeo card game educates - it describes basic chemistry concepts from mixing elements to make compounds, to the fun of medieval alchemy and nuclear fusion. (Alchemy and fusion are the themes of the two most difficult game variants.)

For those who know chemistry, you’ll find the Elementeo card game pays exacting and interesting attention to detail. Examine the two cards pictured above. In the lower-left of each card, you’ll see a symbol representing that card’s “power”. Black rods joining the circles indicate a positive oxidation state, and white rods indicate a black oxidation state. There is little or no gameplay reason to have this information on the card. This is an indicator of the attention to detail and love of designing the game by Elementeo’s creator, Anshul Samar. He went out of his way to go beyond the gameplay and make the game interesting, going beyond the rulebook. This gives Elementeo additional enjoyment, education, and repeat playability.

As the game manual says, Elementeo is not meant to replace chemistry lessons or teaching materials, but hopefully will suppliment them in a fun way. At a meta-level, Elementeo also represents chemistry itself: it successfully combines the gameplay elements of education and fun. This compound is very satisfying.

This experiment shows the concept of energy transfer, how kinetic energy can be transferred from one object to another. While a “drum” and “drum sticks” are required below, this experiment can actually be done with any drum-like and drumstick-like objects. A big inverted tupperware container and two big wooden spoons, for example, will work fine.

Equipment needed:

A drum

Two drumsticks

The Digital Bits Science Lab Experiment:

Use the drumsticks and whack the drum a few times to get a feel for the sound and amount of force needed to get a good drum noise.

Next take both drumsticks, and hit them together. Listen to what kind of sound it makes when one drumstick hits the other one.

Then hold one drumstick in each hand. Place one drumstick on the surface of the drum. Hold the other stick above the drum:

Keeping the end of the lower drumstick on the drum surface, bring the upper drumstick down and strike the center of the lower drumstick.

What happens? It sounds like you’ve just hit the drum, even though you’ve only hit one drumstick with another!

This experiment is an example of the transfer of kineitc energy. When the upper drumstick hits the lower drumstick, the energy from that hit moves from one drumstick to the other. This happens because the sticks themselves are touching. (Kinetic energy moves easily through small solid objects like the drumsticks.) But the lower stick is also touching the drum. So when the upper stick hits the bottom stick, the energy keeps moving: It flows from one drumstick into the next, then from the second drumstick into the drum.

Equipment needed:

Plastic drinking straws

Scissors

The Digital Bits Science Lab Experiment:

What we’re trying to do is to create a simple musical instrument out of a plastic straw. It’s pretty easy. First, cut the top of a straw into what looks like a triangle. (It may help if you squish the straw end first before cutting it – this ensures the cut is the same for the top and bottom of the straw.) When you’re done, one end of your straw should look like this:

Next, blow into the straw. You’ll need to blow pretty hard, and your lips will seal firmly around the straw right at the point where you first made the cut. You may have to move the straw back and forth a bit until you find the right place. The parts of the straw should be flat, and parallel with your tongue – don’t rotate the straw, or the noisemaking will get very difficult or impossible. When you’ve got the right technique, you’ll be rewarded with a buzzing noise coming from the end of the straw.

This is it – we’re making sound! This is the same noise-making concept as reeded musical instruments, like the clarinet and oboe: blowing air over a reed (in this case, our cut straw end) makes that reed vibrate. When it vibrates at the right speed, it makes a noise. A similar technique also allows you to talk. Your vocal cords are just like this straw: you blow air over your vocal cords, and your vocal cords vibrate, and this makes noise come out of your mouth. The difference is that in speaking, your mouth, tongue and many other factors work together. They change various parts of how the air flows and how fast your vocal cords vibrate. This control allows us to form words, sing, and make many other interesting noises.

You can use this concept with our “straw clarinet”, too: cut the straw at the other end (the end you don’t blow into). Shorten it. Make more “straw clarinets”, and cut them to several different lengths. When you blow into these, you’ll find the noise is different from each one. Finally, if you’re really talented, try blowing while changing the tightness of your lips, or varying the amount of air you’re blowing – you’ll find that the noise will change as well.

Equipment needed:

Two measuring cups (one cup must be able to hold at least two cups)

Water

Sugar

One spoon

The Digital Bits Science Lab Experiment:

Make sure that your cup of water and your cup of sugar are filled up precisely.

What do you think will happen when you pour the cup of sugar into the cup of water? You might think that you’ll get a result of two cups of a water/sugar mixture. Let’s try it: Pour the sugar into the water. Stir with the spoon.

Note what happened: one cup of sugar added to one cup of water does not give us two cups!

What’s happened? Why does one plus one not make two? We’ve created a “solution”, and this has interesting properties. A solution is when you mix ingredients, and those ingredients may undergo a physical change as part of that mixing. In this case, our sugar changes physically. Much of it dissolves in water. This is happening on a molecular level – the sugar seems to take up less room, because it’s using the extra space between the water molecules! The density of the water is greater now – we have more molecules crammed into the same space.

On a big scale, this is how the Earth’s oceans are salty, even though we can’t see that salt. Water looks like it may take up a lot of space, but there’s plenty of room to share.

Equipment needed:

A glass. It should have straight sides, not angled.

Water

A bunch of ice

The Digital Bits Science Lab Experiment:

This experiment shows us how water and ice and volume and density have an interesting relationship.

Get a glass and put several ice cubes in it. (The glass should have straight sides – angled sides will get interfere with the ice and affect the experiment.)

Fill the glass up with water, almost to the top. Add a few more ice cubes. And one or two on top of those. You’re trying to get a pile of cubes suspended in the water, above the rim of the glass. The water should be as full as you can get it without spilling over the rim of the glass:

What do you think will happen when the ice melts? The quick answer for some might be that the ice will melt, and that extra water will spill over the rim of the glass, overflowing the glass capacity.

It won’t.

Ice takes up more space than unfrozen, liquid water. The ice in the water displaces the water inside the glass. As the ice melts, that water and the surrounding water move to take up the newly-available space.

The perceived volume of water looks different when a bunch of the water is frozen. Knowing these differences between water and ice can help you better understand how much you’re drinking next time you drink ice water!

Equipment needed:

A bar magnet

Tape

String or thread

The Digital Bits Science Lab Experiment:

We need to identify one side of the magnet – put a piece of tape on one side. Tie the string around the bar magnet so the string is as close to the center as you can get.  When you hang the magnet from the string, it should be pretty well balanced. Hang the magnet so it dangles in the air. Here’s what we’re trying to accomplish:

Next, flick the magnet so it spins. Watch it spin. After a while, it will stop spinning, and one side of the magnet will be pointing north. It does so because that end of the magnet is attracted to the Earth’s north pole. You can double-check by spinning the magnet, or even moving it out of position and then letting it go – the suspended magnet will spin and twist and point back towards north.

The Earth’s north pole is not an actual giant magnet. The north pole is created by effects from the Earth’s constant rotation and its molten iron core. But the effect is similar – it creates a magnetic field so strong, it affects the magnet we’re experimenting with here.

You can experiment to get an idea of size and strength of the Earth’s magnetic field: Take a piece of iron or steel, or any metal you can find that will attract to your magnet. Bring it underneath your suspended bar magnet. When you get close enough, the magnet will bend down and reach for your piece of metal:

Now move your piece of metal away. The bar magnet will turn back into a compass again: it will relax and reorient to point towards the Earth’s north pole. The Earth’s magnetic poles are so strong, and the magnetic fields so large, they affect magnets like your compass from anywhere on Earth!

Equipment needed:

A shoebox

Black duct tape or black paint

A tape measure

Wax paper

Scissors

A heavy blanket

Rubber bands (optional)

The Digital Bits Science Lab Experiment:

To begin with a picture, here’s the finished pinhole camera:

Granted, this isn’t a true pinhole camera. It’s more of a pinhole viewer, or a pinhole camera without any film. With a small modification, you could convert this viewer into a film-based pinhole camera. But for the purposes of this science lab, this pinhole viewer is more fun to use for smaller children, and effectively demonstrates how the eye works, without bringing in the complexity of film and development.

Take your shoebox and make the inside of the lid and box black. Paint it, or use a wide, black tape. You’ll see that due to running out of tape halfway through, I used both techniques in my shoebox. The black color prevents light from bouncing around inside the box, which would interfere with our pictures.

Put the lid on the box. Tape the top on, or put a rubber band around it – we want it in place for the rest of the setup and usage.

Use the scissors to twist out a small hole in the center of one end. See the photo above for detail – this is a small half-inch hole. Don’t make it any bigger.

Now to the other end of the shoebox: we need to make a viewfinder. It’s just a piece of wax paper taped in place over a two-inch by two-and-a-half-inch-wide square. Cut out the square, then tape the wax paper over it. Try to get the wax paper to be as smooth as possible. Wrinkles or ripples aren’t a big problem, but the more you have the more they’ll interfere with your images.

And that’s it – we’re finished, and our pinhole camera is ready. As you use the camera with the directions below, keep two things in mind:

1) The camera works best when you aim at a brightly-lit object. For example, things under full sunlight, or other things illuminated by a bright light bulb.

2) In order to be able to see the image displayed on the wax paper, you need to block out any ambient light: drape an opaque blanket over your head and the camera. That should keep things dark enough to see the light projected on the viewfinder. The majority of light hitting your eyeballs should be what’s coming out of the pinhole camera.

To use the pinhole camera, you need to point the small hole at one end at whatever you want to view. Hold the camera so it’s about a foot away from your face – you may have to move the camera towards and away from your face until you see an image appear on the wax paper. 

As you see the images in the pinhole camera, you’ll see something interesting: the images appear upside down and backward!

Here’s a photo of what I saw during my test:

It’s a little small, as it should be – this was my attempt at taking a picture of the wax paper with a digital camera held at viewing distance.

However, see what happens when we zoom in the picture and flip it upside down:

Still doesn’t make much sense? Perhaps not, but here’s a photo of the actual scene the pinhole camera was looking at:

Seeing the original scene, the pinhole camera version should now make sense. It’s blurred from a combination of the camera having no focus, and the wax paper itself messing with the image quality, but it’s still a snowman standing next to a swingset.

What’s happening here?

Light enters the small hole in our pinhole camera. The small hole only allows a little bit of light to enter, and the light that does enter is projected on the wax paper upside down.

A pinhole camera is a great example of how our eye works: the “small hole” in our eye is the iris. Light enters the iris and is projected on to the back of the eye, the retina. The retina is just like the wax paper. Everything you see, including the words you’re reading right now, is projected upside-down on the back of your eye! The brain takes this signal from the retina and flips it “right side up”.

The eye itself is a pretty remarkable organ, but the basics of photography and sight are pretty simple.

Description: Dissolved copper can be plated onto a metal surface using electricity. Learn how electroplating works.

Equipment needed:

Copper Sulfate. This is one of the most soluble copper compounds, it makes bright blue crystals and dissolves fairly easily in water. You can buy it in hardware stores in several forms, the form I found was Roebic Root Killer (used to clear roots out of sewers and septic systems).

Click the photo to view the larger-sized picture.

A small DC power supply.  A “wall-wart” power adaptor like this one works fine.  I expect that pretty much everyone has at least one or two of these around, orphaned when the electronic gadget that it went with broke down. This power supply came from . . . from . . . well, to tell you the truth, I don’t know what it came from.  All I know is that, whatever it was supposed to provide power to, we don’t have it anymore.

A couple of “alligator clips“, to put onto the wires from the power adaptor. These cost about 50 cents each at the hardware store.

Wire stripper (optional, if you’re handy with scissors)

A screwdriver, that matches the type of screws on your alligator clips.

A small plastic or glass container (something small and disposable, like a small jelly jar or a yogurt cup, is good)

A chunk of copper that will fit easily into your container, and that is thin enough to clip on an alligator clip, and long enough to stick out of the container (a piece of heavy copper wire, or a copper sheet, are both good.  You can get these at any hardware store).  This will be one electrode of your electroplating cell.

A large steel nail that is long enough to stick out of the container.  This will be your second electrode. 

A plastic or wooden stirrer for mixing the solution (a coffee stirrer or a wooden skewer are both good.  Don’t use a metal spoon to stir it, because it will plate copper onto the metal)

A multimeter, either a digital multimeter or an analog multimeter. (It’s optional, you can do the experiment without this, although it does help.)

The Digital Bits Science Lab Experiment:

First, prepare your power supply.  Cut off the end that would normally plug into the piece of electronics, and pull the two strands of wire apart. 

Strip the insulation off of the ends, and put on the alligator clips so that your power supply looks like this:

Put a spoonful of copper sulfate into the container, add water, and stir until the copper sulfate dissolves.

Put in the piece of copper and the nail, with the ends sticking up:

Now, if you have a multimeter, you can check the polarity of your power supply.  Clip the red (+) lead of your multimeter into one of the alligator clips, and the other (-) lead into the other clip.  Set your multimeter to read DC volts, and plug in the power supply.  If you get a positive reading, then you know that the power supply lead connected to your red multimeter lead is the positive lead. If you get a negative reading, swap the power supply leads and try again.

OK, now clip the POSITIVE lead of the power supply to your copper electrode, and the NEGATIVE lead to the steel nail.

If you don’t have a multimeter, just guess which one is which, we’ll be able to figure it out once we turn it on.

Carefully check to make sure that the two electrodes are not touching each other, ideally keep them about an inch apart.

And now, plug in the power supply and watch what happens over a period of about 10 minutes or so.

If the polarity is correct, then you will get metallic copper plating onto the nail, with maybe a small amount of bubbles forming on the nail as well.  Meanwhile your copper electrode will tarnish and turn dark brown or black.  If you leave it running for half an hour or so, you should get a deposit of copper something like this on the nail:

If you have the polarity backwards, then your nail will bubble vigorously, and while there may be a thin film of copper on the surface, it will never build up a significant thickness of copper. 

What’s happening here?

This is an electrolysis reaction.  What we are doing is pumping electrons into one electrode (the nail), while pulling electrons out of the other electrode (the copper).  When you add electrons to a copper sulfate solution, the copper sulfate turns to metallic copper and sulfuric acid. The metallic copper is not soluble in water, so it plates out on the electrode where we are adding electrons.

Meanwhile, at the other electrode we are pulling out electrons.  This makes the metallic copper there react with the sulfuric acid in the solution to make more copper sulfate. 
The overall effect is that copper dissolves from the copper electrode, travels over to the iron electrode, and plates out there as metallic copper.

By adding “smoothing agents” to the solution, it is possible to make the copper plate out as a smooth, shiny metal coating. Similar things can be done with other metals, like gold, silver, zinc, chromium, and nickel.  The metal coatings can be decorative, or they can protect the metal underneath from being corroded, or both.

When heated, air will expand. When cooled, air will compress. Hot air takes up more space than cold air, as this experiment demonstrates.

Equipment needed:

A balloon

A plastic soda bottle (a 2-liter will work well)

Duct tape

A soup pot

A stove

Water

The Digital Bits Science Lab Experiment:

Pour some water into the bottle. Three inches or so will be plenty.

Pull the ballon over the mouth of the bottle. The balloon should be deflated at this point. Wrap a strip of duct tape around the balloon-bottle connection, to make sure the seal is close to airtight.

Fill the soup pot with water. An inch or so will be plenty.

Put the bottle in the soup pot. Put the pot on the stove.

Turn on the stove. You should have something that looks like this:

Wait for the water in the pot to heat up. As it does, the water in the bottle will heat, too. The balloon will eventually inflate:

What’s happening? This science experiment demonstrates how air, when heated, will expand. It expands because air molecules move around a lot more when warmed up. Since they’re moving around more, they bounce around and off each other, and take up more room. We see this as the balloon expands.

To see the opposite of this effect, take the bottle-balloon invention off of the stove. Place it in a container full of ice, or stand it up in a freezer. The balloon will shrink back down and deflate, and the bottle itself might compress inward as the air gets colder!

Another question that people may have is, “why doesn’t the plastic bottle melt on the stove?” Here’s an experiment that shows why the bottle won’t melt, because the water conducts the heat away from the bottle.

See surface tension in action – what happens when you turn it on, and what happens when you turn it off!

Equipment needed:

A wide bowl filled with water

Several index cards

Scissors

Liquid dishwashing soap

An eye dropper, or medicine dropper

The Digital Bits Science Lab Experiment:

Cut an index card into confetti: cut it into strips, then cut those strips into squares. The squares should be no larger than a half-inch on a side.

Mix up the confetti. Make sure none of the pieces are sticking to each other.

Suck a couple drops of liquid soap into the eye dropper.

Sprinkle the confetti in the bowl of water:

Then, use the eye dropper to squeeze one drop of liquid soap directly into the middle of the bowl. Once the soap hits the water, the pieces of paper will fly towards the side of the bowl:

What’s happening? When we drop the soap into the water, it breaks the water’s surface tension right where the soap landed. Think of the surface of the water as a balloon, stretched tight. When the surface tension breaks, the balloon “pops”, and pulls itself away from the break, taking the confetti with it.

If you want to do this experiment again, you’ll need to make sure that any soap is completely washed off any bowl you use. So either use a different bowl, or be sure to wash all the soap off the original one.

A “zoomer” is a small boat-shaped piece of paper that zooms around the surface of water using surface tension.

Equipment needed:

A wide body of water. At the smallest, you should use something like a bathtub. Bigger examples would be a puddle or a swimming pool. The water must be calm, however. If there are waves or splashes, the experiment won’t work.

Several index cards

Scissors

Liquid dishwashing soap

An eye dropper, or medicine dropper

The Digital Bits Science Lab Experiment:

Cut out an index card in a shape like this:

Notice the hole cut near the bottom – be sure to cut out that part, too. This hole is where we’ll drop the liquid soap.

Fill your eye dropper with some of your liquid soap.

Next, carefully drop the zoomer into your water.

Finally, quickly squeeze a couple drops of liquid soap into the hole in the bottom of the zoomer. And the zoomer will zoom! It will move quickly around, and will also stop fairly quickly, depending on the size of your water container.

What’s happening? The zoomer is taking advantage of surface tension – the “skin” that forms on top of the water, allowing small things (like bugs, leaves, and your zoomer) to float on top.

Dishwashing liquid – and every other soap – will break water’s surface tension. The breaking of the surface tension pushes the zoomer forward. The zoomer will continue to move until it runs into water where the surface tension is already broken, or until it runs out of soap!

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 inertia and Newton’s First Law of Motion.

Equipment needed:

One raw egg (or more, if you’re clumsy!)

One hard-boiled egg

The Digital Bits Science Lab Experiment:

This experiment is often described as “how to tell a raw egg from a hard-boiled egg without breaking them”. You simply spin both eggs on a flat surface: The egg that spins smoothly is the hard-boiled egg. The egg that wobbles as it spins is the raw egg.

What’s happening here? The hard-boiled egg spins smoothly and quickly because the egg inside is solid. The raw egg wobbles as it spins because the egg inside is liquid. As the egg is spinning, the liquid inside sloshes around, and affects the egg’s spin. Why does this affect the egg’s spin? It’s because of Newton’s First Law of Motion. This law states: “An object in motion remains in motion, unless acted upon by an external force.” Put more simply, Newton’s First Law says, “if something is moving, it’ll keep moving unless something else stops it”.

Here we have our example of Newton’s First Law of Motion, the raw egg. Try this: give the raw egg a good spin. As it spins, stop the egg by quickly putting your finger on the top of the egg. Then just as quickly, remove your finger. This action should be fast, perhaps half a second at most. When you remove your finger, you’ll see the stopped egg begin spinning again!

The egg keeps spinning after we stop it because the liquid egg inside remains in motion. The shell of the egg was stopped by our finger, but the inside keeps on going.

Within seconds, the raw egg will stop spinning. This is because of many factors: The friction between the table and egg will slow the egg and eventually stop it. Though the liquid inside the egg keeps moving, it too slows down and stops because the hard shell contains the liquid and eventually prevents it from moving.

Description:

A lot of copper mines extract copper from ore by dissolving the copper minerals with sulfuric acid, producing copper sulfate solutions. This lab is one of the ways that they use to convert the copper sulfate into copper metal. Once the copper has been made into metal, it can then be melted down to make copper products like electrical wire.

Equipment needed:

Copper Sulfate. This is one of the most soluble copper compounds, it makes bright blue crystals and dissolves fairly easily in water. You can buy it in hardware stores in several forms, the form I found was Roebic Root Killer (used to clear roots out of sewers and septic systems).

Click the photo to view the larger-sized picture.

Steel wool. Use unsoaped steel wool (the type that is used for sanding varnish), the finer the better.

A small plastic or glass container (something small and disposable, like a yogurt cup, is good)

A plastic or wooden stirrer for mixing the solution (a coffee stirrer or a wooden skewer are both good. Don’t use a metal spoon to stir it, because it will plate copper onto the metal)

The Digital Bits Science Lab Experiment:

Put a spoonful of copper sulfate into the container, add water, and stir until the copper sulfate dissolves.

Tear off a piece of steel wool that is about the same volume as the copper sulfate that you added to the solution:

Put the steel wool into the copper sulfate solution. Use the stirrer to roll it around so that the solution flows through the steel wool. If you use the stirrer to pull the steel wool to the surface of the solution after about a minute, you should see that the steel wool is turning copper colored.

After about 30 minutes, the steel wool should disintegrate into a powder, while the solution changes from blue to green. If you carefully pour off the liquid, you should be able to keep the powder in the bottom.

The powder, which should be reddish-brown, is metallic copper powder. If you dry it and check its conductivity with a multimeter, it should be electrically conductive. If it were just rust from steel wool, it would not conduct electricity after it dries.

What is going on here?

We are starting with copper sulfate in solution (CuSO4), and metallic iron (Fe). It turns out that copper as metal is more stable than iron as metal, so when we put metallic iron into copper sulfate solution, the metal atoms basically switch places:

(Dissolved CuSO4) + (Metallic Fe) ==> (Dissolved FeSO4) + (Metallic Cu)

In the copper mining industry, this process is called “cementation”, and is still used by copper mines that can buy scrap iron cheaply.

How does a color TV show colors? How does a computer monitor show colors? Use a hand magnifier to see how a computer or color TV displays such a wide range of colors.

Equipment needed:

A good hand magnifier. A standard low-power magnifying glass will work, although, like other optics, you get what you pay for. A nice Hastings Triplet Magnifier will cost more, but between the 10X magnification and the clear, distortion-free image I think it’s worth it if you plan to use it much.

A color display. Like the one you are probably using right now to read this. Although, if you only have a low-power magnifier, it will be easier to see how it works if you use a color television instead of a computer display.

The Digital Bits Science Lab Experiment:

Look at the test pattern picture below with your magnifier. (Click on the photo to view the full-size version.)

You can also turn on your TV to something that shows different colors and look at that.

What you will see is that, close up, the screen really only shows three colors: tiny rectangles of red, green, and blue. The rectangles are so small that, from a distance, they all blur together and your eye mixes the colors.

To make different colors, the display makes the rectangles brighter and dimmer. If you look at the test pattern picture, you can see that each color is different brightnesses of the colored rectangles.

Experiment with electricity using a multimeter and a battery.

Equipment Needed:

A multimeter, either a digital multimeter or an analog multimeter.

A battery. A standard AA, C, or D battery will do nicely.

A piece of wire. A straightened paperclip is fine, although any wire long enough to go from one end of the battery to the other will be good.

The Digital Bits Science Lab Experiment:

There are two characteristics of electricity that get measured regularly: the “voltage“, and the “amperage“, or current.

In some ways, electricity is kind of like pumping water. The “voltage” corresponds to how much “pressure” there is forcing the electricity through things, while the “amperage” corresponds to the actual “quantity” of electricity. So, if water were electricity, a big slow-flowing river would have a very low voltage but a very high amperage, while a stream of water jetting out of a power washer would have a very high voltage but a very low amperage. A battery is kind of like a pump for electricity.

So, we will use your multimeter to measure both voltage and amperage of the electricity from a battery, and see how it changes when we “short the battery out”.

First, turn your multimeter selector dial to “DC Volts“, at the lowest range. Touch one probe to each end of the battery. If it is an unused AA, C, or D battery, it should read 1.5 volts. (If you are using an analog multimeter, and the needle tries to turn the wrong direction, just swap the ends of the battery that the probes are touching).

Leaving the probes on the ends of the battery, short it out: take your bit of wire and bend it so the wire touches both ends of the battery. The voltage that you read should drop quite a lot, maybe to almost zero. This is as if we had a power washer, and punched a hole in the hose so that the water could get out more easily, making the pressure drop. If you leave the wire touching both ends of the battery for more than a few seconds, it will start to get hot, so don’t leave it on too long.

Now, turn your multimeter selector knob to “DC mA“. That stands for Direct Current milli-Amperes. Most multimeters only measure up to 250 mA, and when you touch the probes to the battery ends, it will go off the scale (for an analog multimeter), or display some message about being “out of range” (for a digital multimeter). This means that the battery is able to supply a lot more electrical current than your multimeter can measure.

Still leaving the probes on the battery, short it out again with your piece of wire. Now, instead of being out-of-range, the current will drop to something you can read on your scale. Basically, most of the electricity is flowing through the wire, and your multimeter is measuring the current that is “left over”.

Your veins and arteries carry blood and nutrients around your body. Demonstrate “you are what you eat” with a little help from celery.

Equipment Needed:

Glasses

Celery

Water

Liquid food coloring

The Digital Bits Science Lab Experiment:

Pick a couple of colors of food coloring (hint: green may not work as well, as it’s too close to the color of the celery). Put three drops of the food coloring into your glasses, and fill the glasses halfway with water.

Cut your celery so that, when placed in the glass, you have half of the celery in water, and the other half out of water:

Let the celery sit in the glasses overnight.

The next day, look at your celery. In the picture below, you’ll see two celery sticks cut in half. One stick was soaking in blue water, the other in red. The parts labeled “bottom” were the parts submerged in water overnight. The parts labeled “top” were sticking out above the water overnight.

Notice the food coloring leaking out of the “top” pieces.

What’s happening here? When placed in the water, the celery uses it like it always does – it draws the water up into its “vascular bundle“, the thin lines that are the transport system of a celery stalk. Similar to the way blood flows in our own veins and arteries (as pumped around by our heart), the celery’s vascular bundle uses a process called “transpiration” to move its liquid nutrients.

Our bodies need nutrients and liquids to live, just like a stick of celery. Now, we don’t just sit down in a glass of water; we drink it! But the concept is similar – what we take into our bodies spreads to most every other part of our body. We are what we eat (and drink).

If you’ve ever wanted to make your own rainbow, it’s not difficult with a little experimentation.

Equipment Needed:

A flashlight

A large, wide glass (it should be as wide or wider than the head of your flashlight)

Water

The Digital Bits Science Lab Experiment:

In this experiment, we refract light from our flashlight through water. The light, when refracted in the right way, will separate the light into its component colors. The name “Roy G. Biv” is an easy to remember name. It’s also an acronym: ROYGBIV are the first letters of all the colors in a rainbow. The colors in a rainbow are red, orange, yellow, green, blue, indigo, and violet.

A rainbow is also an example of additive color mixing. Additive color mixing occurs when you mix together different colors of light. The light coming from the flashlight is our combination of all colors – it appears white. After shining it through our water, the water separates the white light into the colors that make it up.

To make a rainbow, I used a coffee pot filled with water. Then I placed it on the floor, and shone a flashlight through it, with the refracted light landing on a nearby wall:

Next, you’ll have to play with the flashlight and the water. Move them around. Angle them differently. Move them closer to or away from the wall. The light pattern on the wall will change, and eventually, if you work it right, you’ll see a rainbow at the edges of the light pattern. While the setup you see pictured above worked pretty well, the rainbow picture below was taken by shining the flashlight from underneath the coffee pot, shining the light pattern on the ceiling:

Here’s a close-up of the rainbow picture. Look close, and say hello to Mr. Roy G. Biv!

Refraction happens when when light is bent as it moves. Instead of going in a straight line, it appears to turn, curve or bend.

Equipment Needed:

A flashlight

A glass (it should be as wide or wider than the head of your flashlight)

Water

The Digital Bits Science Lab Experiment:

To make light refract, you need to pass it through two different substances. In this example, the two substances are air and water. Fill up a glass of water. Place a flashlight flat on a table, so that the light is pointed straight through the center of the glass. Turn on the flashlight, turn out the lights, and you’ll see light passing straight through the glass, like this:

Next, simply roll the flashlight. Don’t actually turn it, just move the entire flashlight up and down in relation to the glass. Even though the light is still coming straight out of the flashlight, the light will be refracted (bent) as it moves through the water in the glass. The refractive qualities of the water (and the shape of the water within the glass) will bend the light as you see in the picture below:

Looking at this with better lighting, examine the red line in the picture below. That indicates the path the light takes as it’s refracted. Again, this is caused by the water refracting the light, and the position of the flashlight in relation to the glass:

You’ve probably seen this happen at a restaurant. You’re sipping your drink through a straw. You glance at your glass at just the right angle, and the straw looks “broken”. Let’s take a closer look at what’s happening.

Equipment Needed:

A straw (a stick, a pencil, a chopstick, or any other straight object will work fine)

A tall glass

Water

The Digital Bits Science Lab Experiment:

Fill the glass halfway with water. Put the straw in it. If you place the straw at just the right angle, and view the glass from just the right angle, the straw will appear “broken”:

What’s happening here?

This experiment demonstrates the concept of refraction. Refraction happens when light is bent – it doesn’t always travel in a straight line. The water in the glass bends light as you’re looking at it. So part of the straw looks like it’s in a different place.

This strange appearance of the straw is because of what is called the “refractive index”. The refractive index is the measurement of slowdown light (and other waveform energy) encounters when in a particular substance. The refractive index of water is different than the refractive index of air. Light behaves differently when in water versus air. To us, this simply looks like our straw is bent or broken.

It’s easy, fun, kinda messy, and colorful. Learn about subtractive color combinations. Learn what colors make other colors.

Equipment Needed:

Liquid food coloring

Small transparent glasses (plastic or thick glass juice glasses work well)

Water

The Digital Bits Science Lab Experiment:

Put a couple drops of red food coloring in one glass, and fill it one-third full with water. Do the same with the blue coloring in another glass. Then pour the two colors together into an empty third glass – you’ve got purple water!

Some colors will be “stronger” than others. You may find that, for example, your purple needs three drops of red coloring and only one drop of blue.

Your food coloring set should come with at least three or four different colors. Experiment and find out what colors make other colors:

This is a good time to introduce the subtractive color wheel: there is a pattern to how the colors mix together, and there is a visual way to show it. A subtractive color mix is when you create a new color by mixing different colored liquids together. It looks like this:

See how the electrical conductivity of water changes depending on what is dissolved in it.

Equipment Needed:

A multimeter, either a digital multimeter or an analog multimeter.

Two or three identical containers for water, like drinking glasses or transparent jars

Distilled water. Grocery stores sell bottled distilled water, usually near their bottled drinking water. “Distilled” means it is high-purity water with nothing dissolved in it

Tap water

Baking soda

Sugar

Table salt

A measuring spoon

The Digital Bits Science Lab Experiment:

First, fill one container with distilled water, and set your multimeter to the “ohms” setting for measuring electrical resistance. Touch the multimeter probes together to check that the zero setting is correct. Then, stick the tips of your probes into the water so that the metal part is completely underwater, holding them an inch or so apart. The electrical resistance should be very high.

Next, put some baking soda in the water – about a teaspoon in an 8-ounce glass. Stir it up until the baking soda dissolves, and measure the electrical resistance again. The resistance should be much lower.

Now, fill a series of glasses, with the following

Tap water
Distilled water + 1 teaspoon sugar
Distilled water + 1 teaspoon salt

…and measure the electrical resistance of each. How are they different?

What is going on here?

You should notice that water by itself is not very conductive; that some things (baking soda and salt) make the solution a lot more conductive; while other things (like sugar) do not. What is happening is this: Really pure water is actually an insulator, and does not conduct electricity very well, so it has a high resistance. But, a lot of things that dissolve in water “dissociate”, that is, they break up into electrically charged parts (ions) that can move around. When the ions move, they conduct electricity. Substances that dissolve in water and form ions like this are referred to as “electrolytes”, because they make it possible for water to conduct electricity.

Not all things that dissolve in water are electrolytes, though – the sugar will not make the water very conductive, because sugar dissolves without breaking up into ions. If your sugar did increase the conductivity a bit, it was probably because it had small amounts of some impurities that were electrolytes.

The tap water should have been more conductive than the distilled water, but not as conductive as the water with salt or baking soda dissolved in it. This is because the water out of your tap is not pure, it has minerals like calcium carbonate dissolved in it. Depending on where you live, you could have “hard” water (which has a lot of dissolved minerals in it and is quite conductive), or “soft” water (which has very little dissolved minerals, and can be almost as non-conductive as distilled water).

You can check the conductivities of other liquids, too, like cooking oil, vinegar, or soda pop. Also, see how adding just a little bit of baking soda or salt to water changes the conductivity, compared to adding a large amount.

Description:

A simple demonstration of electrolysis – electrocuting water to convert it into hydrogen.

Equipment Needed:

A 9-volt battery

Wire (something low-gauge and flexible is preferred, like copper wire)

Scissors

Wire stripper (optional, if you’re handy with scissors)

Tape (durable tape is required, like duct tape or electrical tape)

A glass of water

Salt

The Digital Bits Science Lab Experiment:

This experiment is a simple demonstration of electrolysis. Electrolysis is the method of breaking apart compounds into their original elements by passing an electric current through them.

Put simply, this experiment shows that if you electrocute water, you’ll get hydrogen.

First, we need to make the electric device that will make the electrolysis happen: get the 9-volt battery, your wire, the scissors and tape. Start stripping the ends of the wire. You will need two strands of wire at least six inches in length. Use the wire stripper or the scissors to strip the rubber sheath from both ends of each wire with the scissors. This will expose the wire itself:

After you’ve stripped both ends from both wires, take one wire and securely tape one stripped metal end to one terminal of the 9-volt battery. Next, do the same with the second wire – tape it to the remaining battery terminal. The result will be our electrolysis device, all ready to go:

The rest is easy:

Get your glass of water. Put a tablespoon or two of salt into it. Stir the salt to dissolve it. The water will become a little cloudy.

Get the electrolysis device. Dip both ends of the wire into the salt water.

You will immediately see bubbles start to fizzle off of one wire. (If you don’t see bubbles, then check to make sure that your wires have a good connection to the battery, and that the battery still holds a charge.)

What’s happening here? These instructions are simple do-it-yourself electrolysis: when you electrocute water (which is made of hydrogen and oxygen), the electricity breaks apart water molecules. The bubbles you see are the hydrogen from the water being released. Salt water improves the electrolysis reaction - fresh water (like in the picture above, since cloudy salt water was difficult to photograph) will still give you bubbles of hydrogen, but it won’t be as impressive as with salt water.
 

A simple demonstation of “muscle memory” and the subconscious actions of our body.

Equipment Needed:

You

A doorframe or wall

The Digital Bits Science Lab Experiment:

This experiment will assume you’re standing in a doorframe, but really the experiment will work fine with any heavy, large object.

Stand inside the doorframe. Stand normally, but stand so that one arm is directly against the wall. Push outward – away from your body – with your wall-touching arm, as if you wanted to flap your arm. It will be stopped by the doorframe, as in the picture below:

Now, keep pushing! And push some more! Count slowly to thirty, pushing your arm out against the wall the entire time.

Then, step away from the wall. Relax both your arms, and let them hang limp at your side.

But watch what happens: the arm you were pressing against the wall will start to rise!

What’s happening here? Your muscles have memory: when you press your arm against the wall for so long, your arm muscles get so used to pushing against the wall, they continue to push even after you’ve stepped away. And since your arm muscles are still pushing, your arm raises up into the air. Evenutally, your arm muscles will realize you are no longer pushing, and your arm will lower back down.

“Your Multimeter and You”: use a multimeter to measure electrical resistance of things, including yourself.

What is a multimeter? Multimeters are instruments to measure several different things, including electrical conductivity, electrical current, and electrical voltage. You can get very cheap ones (see the photo below). You’ll find them at hardware stores for approximately $10 – $20, or you can spend tens, hundreds, or even thousands of dollars for really high-end professional models.  I recommend one of the cheap ones. These can either have a needle and dial reading like the one shown here (analog multimeters) or a numerical display (digital multimeters).

Equipment Needed:

A multimeter, either a digital multimeter or an analog multimeter.

You

A metal object, like a coin

A piece of plastic, wood, or glass

A pencil with the eraser pulled off of one end so that you can see the pencil lead

The Digital Bits Science Lab Experiment:

A multimeter has many different settings, the one we are going to use is one of the ones marked “R” (for resistance) or “Ohms”:

This setting is used to measure how easily electricity flows through an object. What the multimeter does is this: it has a battery inside that is connected to the probes.  When you touch the probes to an object, electricity flows from the battery through the object.  If a lot of electricity flows, that means the object has very little electrical resistance, while if hardly any electricity flows, that means the object has very high electrical resistance. The multimeter measures the electrical current flow, and uses this to calculate the resistance of the object in units called “Ohms”.

So, turn the settings selector on your multimeter to measure resistance. First, check the calibration of your multimeter.  With the probes not touching each other, the reading should be “infinite resistance”, meaning no electricity is flowing. When you touch the probes together, the multimeter should read zero resistance, meaning that the current is flowing through the probes as quickly and easily as possible.

Now, we are ready to make some measurements. 

First, check a metal object: the resistance should be very close to zero ohms because metals are very good conductors of electricity.

Next, plastic or wood: the resistance should be extremely high, because these are all very bad conductors of electricity (insulators).

Now try the pencil: touch the multimeter probes to the lead on each end of the pencil.  You should get a reading of somewhere around 10 to 100 ohms. This means that the pencil lead (graphite) will conduct electricity, but that it is not as good of a conductor as most metals.

Finally, try yourself: grab hold of one probe in each hand, and see what your resistance is (don’t worry, the battery in the multimeter is not strong enough to give you a shock).  If your hands are dry, you will probably have nearly infinite resistance.  If your hands are sweaty, or if you lick your fingertips before taking hold of the probe, you should have
a resistance somewhere around 50,000 ohms.  If you touch the probes to your tongue, the resistance should be much lower.

So, this means that while your body has a lot of resistance, it has less resistance than an insulator like a piece of wood.  This is why you can get electrically shocked (because electricity can flow through your body), and why electrical appliances near water are a bad thing (because if you are wet, you have a lot less electrical resistance than if you are
dry).

Possibly the simplest and cheapest kite in the world.

Equipment Needed:

A standard notebook-size piece of paper. (Scrap paper from a printer is fine.)

A spool of sewing thread

Scissors and tape

Something to poke holes in paper (a pencil or pen tip is fine)

The Digital Bits Science Lab Experiment:

Take the sheet of paper, fold it diagonally as shown in the picture below, and cut off the tag end of the paper to make a square. Save the tag end for later, you will need it to make a tail for the kite.

Fold the square part as shown below, then flip over and fold the other side the same way.

Once both sides are folded, open it out and poke holes on both sides at the points shown.

Then trim off the tips with the scissors.

Take the tag end that you cut off the paper to make it a square, and cut this into four strips as shown. Tape these end-to-end to make a tail.

Tape the tail to the kite.

Then tie a piece of thread through the hole that you punched in the paper, with the thread about as long as is shown below, to make a “bridle”. Tie a loop in the middle of the thread.

Now take the rest of your thread and tie it to the loop in the bridle, and your kite is ready to fly. Take it outside and give it a shot. It doesn’t take much wind to fly these kites, so you can fly them even on fairly calm days.

How do kites work?

When the wind hits them they divert the air, forcing it forward and down. At the same time, the wind makes a force on the kite, forcing it backwards and up. This is the basic principle that makes “lift” in airplanes. The string keeps the kite from simply being blown backwards, so it has to go upwards.

Since these kites are so cheap and easy to make, you can try lots of experiments:

- What happens if you make the tail longer or shorter?

- What happens if you make the “bridle” string longer or shorter?

- What happens if you cut holes in the kite?

- Can you string a bunch of kites in a chain? How far apart do they have to be in order to work properly?

- Can you think of ways to change the shape of the kite to make it fly differently?

Learn about friction – use a pencil to pick up thousands of grains of rice. (And no, this won’t take hundreds of years.)

Equipment needed:

A non-breakable bottle (a 20-ounce pop bottle works fine)

A pencil (it should be at or near full-size)

Rice (you’ll need almost a pound for a 20-ounce pop bottle)

A funnel

The Digital Bits Science Lab Experiment:

Use the funnel to pour the rice into the pop bottle. Leave a few inches of space at the top.

Insert the pencil into the bottle’s hole, and start stabbing!

After a few stabs, the rice will settle, and you’ll feel the pencil getting stuck in the rice as you try to pull it out.

It will take some practice and experimentation as to what type of stabs work best. (Quick stabs work well.) What you’re trying to do is to get the pencil “stuck” in the rice. If you get it stuck just right, you can carefully lift the pencil, as well as the entire bottle of rice!

This experiment teaches about friction. Friction is the resistance you feel when one object is moved against another. When you’re walking outside on a snowy day, you might step on ice and slip. The ice is slippery because there is a low amount of friction between your feet and the ice. But if you sprinkle sand on the ice, you can walk without slipping – the sand increases the friction to make walking safer.

When you stab the pencil into the rice and it “sticks”, the rice is packed against other grains of rice, with are all contained by the bottle. The friction between the rice and the pencil is strong enough to hold the pencil in place when you lift the bottle with it.

A leaky bottle can teach how air pressure works, and how strong air pressure is – It can stop water from flowing!

Equipment needed:

One clear, plastic bottle with an airtight top (a two-liter pop bottle with a screw-on cap works great)

A large bowl (something big enough to hold all the water that may be in the plastic bottle)

The Digital Bits Science Lab Experiment:

Punch very small holes (less than a quarter-inch diameter) in the bottom of the plastic bottle. Three holes works well.

Fill the bottle with water. The holes will start draining the water, so you may have to turn the water on full blast to fill, or use one hand to cover the holes.

When the bottle is full, screw the top on tight. If you lift the bottle up, there may be a few drips, but after a few seconds no water should flow out. (If water still glugs out of the bottle at this point, you’ve made the holes too big.)

Unscrew the cap.

The water will start pouring out the holes in the bottom.

If you screw the cap back on before the water drains, the water flow will stop.

What’s happening here? Many things, but one big one is air pressure. With the cap screwed on, the water stays in the bottle. This is because the water needs more air to take the space at the top of the bottle, to replace the space previously filled by the water. Gravity is pulling on the water, and the water tries to flow out, but needs the air to expand and take up more space to do so. The air pressure isn’t changed – the air won’t expand or contract from the very small pull of the water. The air pressure is stronger than the pull of gravity. So the water stays in place.

If the cap is screwed on, there is nothing to replace any space used by the water. So the water doesn’t move. Unscrewing the cap allows air to flow into the bottle, which allows the water to pour out from the bottom, and the air takes up more and more space at the top.

See what colors combine to form other colors. Make a CD spinner to improve the testing, giving you a color combiner that can be reused with any color you want.

Equipment needed:

One CD that’s no longer needed (like a music CD, a “Free AOL CD”, or a blank computer CD)

Washable markers

A penny

A pliers

A gas flame (like from a gas stove, gas fireplace, or propane grill)

The Digital Bits Science Lab Experiment:

Hold the penny with the pliers. Heat the penny for thirty seconds over a gas flame. (A candle won’t work – it’s not hot enough.)

Hold the CD carefully, and use the pliers to gently push the penny into the CD’s center hole:

The penny will be hot and the CD will melt. Try to place the penny so it bisects the CD. Hold it there until the penny cools enough for the CD plastic to harden and hold it in place. (Blow on the penny, and this will take only another ten or twenty seconds.)

Now you’ve got something special: It’s a washable, CD spinner.

Get the washable markers and color the CD with a couple of colors. We’ll use red and blue in our example. Make sure to color so the whole of the CD is covered, and make sure your colors alternate frequently:

Now spin it!

You’ll see the red and blue will combine and form purple:

When you want to try different colors, it’s easy – the CD and washable markers come off just by rinsing:

Use this experiment to learn about colors and color combinations. And have fun spinning.

A hovercraft works because of air pressure: it uses a motor to create a cushion of air. The hovercraft floats on this cushion, allowing it to move over land and water.

Build your own balloon-powered mini-hovercraft. It’s a great way to demonstrate the basics of how a hovercraft works. It also demonstrates the concept of air pressure.

Here’s what we’ll build: our balloon-powered hovercraft, all ready for launch:

Equipment needed:

Balloons

Duct tape

A plastic plate with raised edges. The edges themselves should be smooth if possible, not ridged. (Notice that the plate used in the pictures below has ridged edges. It works, but not as well as one with smooth edges.)

A straw

A sharp knife

The Digital Bits Science Lab Experiment:

Cut a straw in half. Stick the straw into the balloon. Duct tape around where the straw meets the balloon mouth. Test for air-tightness: you should be able to inflate the balloon by blowing into the straw. After you inflate the balloon, pinch the straw closed. If you hear the hiss of air, there’s still a leak – add more duct tape or pinch around the seal to close all leaks.

Cut a hole in the middle of the plate. It should be no bigger than the straw.

Turn the plate upside-down. Place the straw/balloon part into the hole in the plate. The straw can extend into the other side of the plate, but shouldn’t be lower than the plate’s edges. (When the plate is sitting upside-down, it should rest evenly on its edges. The straw should NOT be pushing the plate into the air.) Here’s a shot of the bottom of the hovercraft:

Use duct tape to make a seal where the straw enters the plate.

Your final product looks like this:

Here’s detail of the bottom of the hovercraft (which is actually the top side of the plate):

Get another straw. This will be our removable inflater for the balloon.

Crimp the end of the inflater straw. It should look similar to this:

Shove the crimped straw into the balloon-attached straw. If you push firmly, you’ll have a pretty good air seal between the two straws. Blow to inflate the balloon. When you’ve inflated it, you can pinch the straw/balloon part to hold the air in until you’re ready to run the hovercraft.

Here’s a shot of me pinching the hovercraft straw to keep air in the balloon. The inflater straw is still inserted:

Place the hovercraft on a very flat surface, like a table or counter-top, and release the pinch.

The balloon will start pushing air under the plate. The air pressure under the plate will build until the plate floats on a cushion of air. When that happens, the plate will skitter back and forth by itself, until the balloon runs out of air. When the balloon is empty, you can “refill” it again with your inflater straw.

Try different things when you launch the hovercraft: Try spinning it. Try putting it on a hill. Put it in water. Try building hovercrafts with different balloons, and enjoy the results!

Surface tension is a special attribute of water. When water is exposed to air, it forms a thin “skin” that keeps the water together. This is how some bugs skim over a water’s surface: surface tension keeps them from sinking into the water.

This experiment demonstrates surface tension. In it, we can join together two separate streams of water.

Equipment needed:

A used 2-liter pop bottle or milk carton (or some similar plastic container you can cut holes into)

A sharp knife (for cutting small holes in the bottle)

Water

A sink

The Digital Bits Science Lab Experiment:

Cut two vertical holes in the bottle. They should be about 1/8 of an inch apart. They should be no more than 1/4 of an inch tall.

Hold the bottle over a sink. Fill the bottle with water.

Water will start to pour out of the holes. If you’ve cut them right, the water should form two streams, and shoot straight out from the bottle. Adjust the cuts if needed to make sure this happens.

Join the water streams by “pinching” the streams together, right where they leave the bottle. Your pinch should push the streams together, mixing their water into one stream.

When you take your hand away, the streams will be joined.

Next try “wiping” the streams: with a flat hand, quickly wipe your palm down the bottle, over the streams. If you do it right, the single stream will separate into two streams again.

What’s happening here?

The streams of water start off separated, since the water is coming out of two different holes when you start the water flow. But when you “pinch” the streams together, you’re forcing the water streams to join together. And because of surface tension, the streams decide to stay joined even after you finish the pinch. When you “wipe” your hand down the streams, you’re breaking the surface tension and the streams once more become separated.

This experiment shows how to separate pepper and salt using a balloon and static electricity.

Equipment needed:

One balloon (a comb and some plastic hairbrushes will also work well for this, particularly if you’re worried about the balloon bursting)

A cloth (wool will work best)

Salt

Pepper

Safety glasses

The Digital Bits Science Lab Experiment:

Wear safety glasses for this experiment – you don’t want salt or pepper getting in your eyes.

Mix a small pile of salt and pepper. The challenge here is to separate the salt from the pepper.

It’s easy if you have a balloon: inflate the balloon. Rub the cloth on the balloon, and the balloon will become negatively charged. This means the balloon will become attracted to objects that have a different charge. Luckily for us, the salt and pepper fall into this category.

After charging the balloon, hold it above the salt and pepper mixture and slowly bring it closer. You’ll see the pepper fly up and stick to the balloon, leaving the salt behind. The salt stays put because it’s heavier than the pepper. This is why you want to move slowly, because if you move too close too fast, the salt will also fly up and attach to the balloon.

When you’re done, you can either wipe or wash the balloon off to remove the pepper. Don’t pop it, or you’ll get pepper everywhere! 

You can direct the flow of water without touching it. All you need is a little static electricity.

Equipment needed:

One balloon

A sink with running water

A cloth (wool will work best)

The Digital Bits Science Lab Experiment:

Turn on the water faucet. Make sure the water flow comes out very slow and thin (a thinner water stream is easier to redirect).

Rub the balloon with the cloth to build up a static electric charge.

Bring the balloon close to the water stream. When the balloon gets close to the water, the negative static charge will attract the water and “pull” the stream towards the balloon:

The charge will wear off within a few seconds, so the effect won’t last long!

Static electricity is the transfer of electrons from one material to another. You can see the effects of static electricity using balloons.

Equipment needed:

Two balloons inflated to the same size.

A light stick approximately two feet long (a couple of long matchsticks or chopsticks will do the trick)

Duct tape, masking tape, or some other heavier-duty tape.

String

A piece of cloth (wool works best). Something sock-sized or washcloth-sized will be fine.

The Digital Bits Science Lab Experiment:

If needed, create your “stick”. In the pictures below, I used a couple of long matchsticks, and just duct-taped them together. The goal is to create a stick long enough to suspend two balloons, and prevent them from easily touching a wall.

Cut two equal lengths of string, approximately 2 feet long. Tie each balloon to the stick using its own piece of string. Make sure the baloons are both at the same level.

Tape the stick on to a wall. Inside of a room entrance worked for me. This allows the balloons to extend into a room, while being held away from the walls.

The balloons may stick to each other slightly, or be repelled slightly, as we see here:

Now, rub one of the balloons with the wool, and let it drop. What happens? It may “bounce” away from the other balloon. It may stick to it.

Rub the second balloon with the wool, and let it drop. Both balloons should bounce away from each other. If you’ve built up enough of a charge, one balloon may even bounce off of the other balloon and stick to the wall:

What’s happening here?

Static electricity is the imbalance of electron charges. When you rub a balloon with the cloth, you’re actually moving electrons from the cloth to the baloon. The addition of the electrons gives the balloon a negative charge.

A couple simple rules when dealing with static electricity:

Objects will repel each other if they have the same charge. A balloon with a negative charge will repel other balloons with a negative charge. This is why the balloons pushed away from each other when we rubbed them both with the cloth.

Objects will attract each other if they have different charges.A balloon with a positive charge will attract other things with a negative charge. This is why rubbing a balloon attracts it to the wall – the wall has a more positive charge, which attracts the balloons more negative charge.

We use balloons in this experiment because they’re very light: the static attraction/repulsion is easier to see. But you can charge other things, too. See what other things you can make stick to the balloon (hint: you’ll have good luck with thin, light things, like paper, or hair).

Oil and water don’t mix. Putting food coloring in oil, and letting it slowly settle into a glass of water will create “water fireworks”, little streamers of color cruising down through the water.

Equipment needed:

Liquid food coloring

Cooking oil

Tall glass

Short glass

Cold water

The Digital Bits Science Lab Experiment:

Fill the TALL GLASS with cold water. Don’t fill it all the way – Leave at least an inch of space at the top.

Pour about an inch of cooking oil into the SHORT GLASS. Put two or three small drops of your favorite colors of food coloring into the cooking oil.

Stir the oil/coloring mix slightly, just enough to break up the globs of color a little bit.

Slowly pour the oil from the short glass into the tall glass.

The oil will rise to the top of the water, and you can watch the globs of food coloring slowly settle to the bottom of the oil. In a few seconds, the color will begin floating down from the top of the oil mixture. It will hit the oil/water separation, and coloring will stream down through the water, looking like little streamers of color:

This experiment shows how oil and water don’t mix. When you mix them together, they’ll separate. The food coloring “fireworks” help add some pizazz.

Because we don’t want the food coloring mixing with the water – we instead want to see our colors streaming trails through the liquid – we use cold water. See why cold water will slow down the mixing process.

This experiment shows the concept of energy transfer, how kinetic energy can be transferred from one object to another. It also demonstrates a basic concept of Einstein’s E=mc² equation, about mass-energy equivalence.

Equipment needed:

A basketball

A tennis ball

A superball (or any very small, light, solid rubber ball)

The Digital Bits Science Lab Experiment:

Go outside with all your balls, and find some solid, hard ground, like a driveway or playground.

Drop the basketball. Do the same with the tennis ball and superball. Watch how high they bounce.

Now, take the basketball and the superball. Place the superball on top of the basketball. Making sure the balls are still touching, drop them on the pavement. The balls will hopefully hit the ground while still touching. And when they hit, watch the bounce! The smaller ball will fly up a lot higher than usual, and the basketball won’t bounce as high.

This Science Lab experiment shows us how kinetic energy can be transferred from one object (the basketball) to another (the smaller ball). During the drop and pavement bounce, the basketball’s energy is transferred to the smaller ball: the smaller ball flies high, and the basketball – with less energy now – doesn’t bounce as high.

This also is a good example of “mass-energy equivalence“. Einstein’s E=mc² equation tells us that the amount of energy something has is related to its mass. The basketball is more massive than the smaller balls, so it has more energy to transfer to those balls. This is why they fly up in the air much higher – during the ground bounce, the littler ball just got handed a lot more energy, far more than it gets when bouncing on its own.

Earth’s atmosphere insulates and heats the Earth. This experiment is a great visual of the Greenhouse Effect.

Equipment needed:

Two identical glasses, filled with cold water.

A sealable bag (like a Zip-Lock bag, or a bag you can twist-tie closed). It must be large enough to completely cover and seal over one of the glasses.

A thermometer

The Digital Bits Science Lab Experiment:

Place both glasses in direct sunlight, or very close to a very bright light.

Wait for two hours.

Open the bag, and take the temperature of the water in both glasses.

Note the difference between the measurements. Which one is warmer?

Why did this happen? As the sunlight (or bright light bulb) heated the water, the warmer air around the water was trapped inside the glass covered by the bag.

This is an example of how the Greenhouse Effect and the Earth’s atmosphere work – they are good things, to an extent, because they keep heat on our planet and prevent it from getting too cold, and that keeps us alive! But it’s a tricky balance, because by changing Earth’s atmosphere (or by using a thicker bag to cover our glass), we might increase the overall temperature of our planet.

This experiment shows how water can conduct and absorb heat.

Equipment needed:

Water

Balloons

A lit candle

The Digital Bits Science Lab Experiment:

Blow up a balloon. Hold it over the lit candle. Boom! The balloon explodes! The lit candle heated the balloon, weakened and melted it, and the balloon exploded.

Now take another balloon, and fill it halfway with water.

Hold that same balloon over the candle. Do you think the balloon will explode, splashing water everywhere?

Nope.

You can have the candle flame actually touch the balloon, and the balloon won’t break!

The water in the balloon is absorbing the heat from the candle. The balloon conducts heat very well, so the candle flame transfers to the water without harming the balloon.

This is an experiment that shows the concept of heat being energy.

Equipment needed:

Hot water

Cold water

Two identical glasses

Liquid food coloring

The Digital Bits Science Lab Experiment:

As water gets warmer, water molecules move around faster and faster. We can’t see a molecule without help, of course, but we can still see the effects of hot and cold water molecules.

Fill your glasses. One should have hot water in it, the other cold water. Pick a color of food coloring.

Put three drops of food coloring in each glass.

Wait, and watch what happens.

You can tell from the food coloring which glass is holding the hot water, and which is holding the cold. The cold water contains less energy – the water molecules are moving slower, and therefore the coloring mixes slower.

The hot water’s molecules are moving faster – the water contains more heat, and therefore more energy. So the food coloring mixes faster.

What is a chemical reaction? Experiment with baking soda and vinegar

Equipment needed:

Baking soda

Vinegar

A skinny glass

A plate (to catch spills)

The Digital Bits Science Lab Experiment:

There’s nothing like a classic. And an experiment with baking soda and vinegar is about as classic as you can get.

Get your skinny glass and put it on your plate.

Prepare 1/4 cup of vinegar and set it aside.

Prepare one heaping tablespoon of baking soda and set it aside.

Pour your 1/4 cup of vinegar into your glass.

Then, dump the heaping of tablespoon of baking soda into the glass. You’ll see a fizzing and bubbling and percolating and growing column of stinky, smelly soda and vinegar mixture:

This is a chemical reaction, where a combination of two different things produces a third: The vinegar and baking soda mixture is making carbon dioxide. This CO2 is the bubbles and fizzing you see.

Younger children will love this one because it’s always fun to play with things that fizz and bubble and move on their own. Older children will be able to learn a simple way to make a chemical reaction. They can experiment with the ingredients and presentation: What if you add more baking soda? Or use more vinegar? The glass we use is skinny and thin to better show off the growing, bubbling effect – how much vinegar and soda would we need to overflow the glass?

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!

Learn about the elements and periodic table.

Equipment needed:

There’s nothing like a good visual. In this case, go to the Periodic Table website. In addition to the excellent resources on the website itself, it allows you to get more information and close-up views of the elements, including a snazzy rotating videos and 3D-interactive visuals.

The Digital Bits Science Lab Experiment:

Older children will get exposure to the elements themselves, which – in the way this website presents them – are truly impressive and fun to look at. Make sure you see the periodic table placemats and 3D posters!

As the child gets older, she can learn about the elements, what makes them unique, and unique stories and characteristics about each one.

Learn about colors and color mixing with light.

Equipment needed:

There are a few options, depending on the personality of the child and the amount you’re willing to spend:

The Metropolitan Museum of Art Color Magic Puzzle is a puzzle consisting of sliding colored plastic squares. The object (and the fun) is to slide the squares around the puzzle, mixing and creating different colors as you do so.

The Magna-Tiles Clear Colors 32 piece set is a construction set of translucent colored plastic triangles, squares, and similar straight-edge shapes.

For larger construction projects or larger groups of children, a Magna-Tiles 100 piece set is also available.

The Digital Bits Science Lab Experiment:

This combining of different colors of light to form other colors is called additive color mixing. Using the Color Magic Puzzle or Magna-Tiles sets illustrate how blending different colors of light gives you different colors.

Younger children will probably love the Magna-Tiles, since they’re less goal-oriented; it’s fun just to stick the things together. Older children can be taught about color combinations, and would further appreciate the Magna-Tiles as well as the Color Magic Puzzle.

Ants. They’re not just for driveways anymore.

Equipment needed:

An ant farm. While there are the traditional sand-filled ant farms, my latest favorite has been the Fascinations Antworks ant farm. The tunnel and farm medium, instead of sand, is a cool-looking gel. It’s cleaner. The tunnels are more stable, and are less likely to collapse from vibration or movement of the ant farm. The gel also provides food for the ants, so you don’t have to feed them. And the gel is transparent, so you can easily see the ants and their tunnels in three-dimensional glory.

Ants. You can get 25 Western Harvester ants for about $5. If you don’t want to mail order them, you can always dig some up in the back yard. Note that Western Harvester ants are medium-sized with larger mandibles. They’re great for ant farms – very visible and active – but they’re not for cuddling: They can and will bite (or pinch), so keep them in the ant farm.

The Digital Bits Science Lab Experiment:

An ant farm is a great intro into several biological and behavioral concepts:

There is, of course, the study of insects and ant biology. Watching them dig tunnels is fascinating. And not in a lava-lamp kind of way, but in a logical, workhorse way: Ants are directed by very simple rules, but those simple rules can produce complex results, like the complexity of the ant community and the tunnel systems.

Also make notice of the group effort: Like Egyptian slaves laboring to build the Pyramids, or herds of animals fighting off predators, an ant farm is a great way to show how group effort and cooperation can accomplish more than a single individual ever could.

And, perhaps the most important thing a child will enjoy about an ant farm: Bugs! What young child doesn’t like creepy crawly bugs? The ant farm lets them get as close as they want, without worrying the parents.

For more insectile fun, check out The Backyard Arthropod Project. The author’s project is to catalog as many arthropods (mostly insects and arachnids) as possible inside and around his house. Great for close-up pictures of arthropods, as well as interesting stories and information about each one.

Learn about colors and color mixing while splashing around.

Equipment needed:

Crayola® Bathtub Tints, also called “Color Dotz”. If you’re really ambitious, get the Crayola® Bathtub Tints – 3 Pack.

Water. H2O. Lots of it. Favorite locations could be an outside kiddie pool, or a bathtub.

The Digital Bits Science Lab Experiment:

The Color Dotz bathtub tints aren’t much more than small dry tablets containing a little washable dyes. They fizz when placed in water, releasing the coloring and making your bath or pool a swirly, colorful whirpool of mixing colors. (While I haven’t had problems, and these are listed as “non-toxic, non-fragrant, biodegradable, non-irritable to skin and eyes, and easy-to-clean”, do a test run to make sure the tints won’t stain your bathtub!)

The benefit to the child depends on their age:

For very young children, this is a fun and wet way to learn about colors while playing with bubbling, fizzy tablets.

As the childen get older, you can introduce the concept of mixing colors, how “red plus blue equals purple”: Hand them the tints for red and blue, let them play, and show how the red and blue water mixes to make purple.

This combining of dyes (and paints and other liquids) to create new colors is called “subtractive color mixing”.

Older children could experiment with the fact that the Color Dotz are made primarily from sodium carbonate, sodium bicarbonate and citric acid. (The fizzing process is caused by water causing a reaction between the sodium carbonates and the acid. The gas released is carbon dioxide.)

For those older kids, there are a lot of fun things you can do with Color Dotz:

Load a balloon with a few Color Dotz, add water, and tie up the end. Stand back – the releasing gasses will expand and explode the balloon! (I probably shouldn’t have to say this, but just in case: DO THIS OUTSIDE!)

Drop Color Dots on the ground outside, and run the hose or sprinkler. Follow the path of the water. Water tracing techniques like this are used by professionals that need to trace currents, detect leaks, flow studies, and for many other uses. (The difference with the professionals is that they use slightly different dyes – these are often flourescing dyes, for easier identifiation and tracking.