Earth Day Science

 - by KitchenPantryScientist

Saturday April 22nd is Earth Day, so get outside and show our home planet some love! Whether you’re picking up trash or visiting a park, it’s always fun to throw some science into the mix.

Here are some of our favorite environmental science experiments. Just click on the experiment names for directions and photos. You can find more fun outdoor experiments in my books “Kitchen Science Lab for Kids” and Outdoor Science Lab for Kids (Quarry Books.)

from "Outdoor Science Lab for Kids" (Quarry Books)

from “Outdoor Science Lab for Kids” (Quarry Books)

Homemade Sweep Nets: Make a sweep net from a pillowcase and a hanger to see what arthropods are hanging out in your favorite outdoor spaces.

Window Sprouts: Plant a bean in a plastic baggie with a damp paper towel to see how plants need only water and air to sprout roots and leaves.  Here’s a short video demonstrating how to make a window garden.

Homemade Solar Oven: Using a pizza box, aluminum foil, plastic wrap, and newspaper, you can harness the sun’s energy to cook your own S’mores!

Nature Walk Bracelets: Wrap some duct tape around your wrist (inside out) and take a walk, sticking interesting natural objects like leaves and flowers to your bracelet. It’s a great way to get outdoors and engage with nature!

Carbon Dioxide and Ocean Acidity: See for yourself how the carbon dioxide in your own breath can make a water-based solution more acidic. It’s the same reason too much carbon dioxide in Earth’s atmosphere can be bad for our oceans.

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Plant Transpiration:  See how trees “sweat” in this survival science experiment.

Earthworm Experiment:  Do you know what kind of earthworms are living in your back yard?

Composting: Be a composting detective. Bury some things in your back yard (away from power cables) and dig them up in a few months to see how they look. Composting reduces methane gas emissions (a greenhouse gas) from dumps.

Diffusion and Osmosis: See for yourself how the chemicals we add to water, put on our streets to melt ice, and spray on our lawns and crops can move into our soil, ground water, rivers, lakes and oceans.

Solar Water Purification: This project illustrates the greenhouse effect and is a fun “survival science” experiment. Requires hot sun and some patience!

Citizen Science: Don’t forget about all the real environmental research projects you can participate in through Citizen Science programs all around the world!

For mores activities and games, check out NASA’s Climate Kids website, to see a kid-friendly diagram of the water cycle, click here or just get outside and enjoy the beautiful planet that sustains and nurtures us.

Nail Polish Marbled Eggs

 - by KitchenPantryScientist

Nail polish marbling is tons of fun and yields stunning results. However, it takes some eye-hand coordination, practice and patience, so I’d recommend it for ages 10 and up. My 11 YO loved it!

KitchenPantryScientist.com

KitchenPantryScientist.com

Hint: You’ll have to work reasonably fast for good results. Gloves are a must, and do this in a well-ventilated area to avoid breathing too many nail polish fumes.

You’ll need:

-eggs with the raw yolks and whites blown out (We poked generous holes in each end of our eggs using a thumb tack, scrambled the inside with a toothpick and used syringes and balloon pumps to blow out the raw whites and yolks. It takes patience, and you’ll lose a few eggs to cracks.)

-a container that can be thrown away

-nail polish in two or more colors

-a toothpick

-water

1. Fill your container 3/4 full of water.
2. Drip nail polish, a drop at a time into the center of the water. Each drop should be in the center of the one before. Don’t worry if they spread out, just keep adding more. You’ll have to work fast, or the polish will dry on top of the water. It may take practice.

Kitchen Pantry Scientist.com

Kitchen Pantry Scientist.com

3. Use tip of the toothpick to draw designs in the polish. Start by pulling it out from the center or pushing it into the center.

KitchenPantryScientist.com

KitchenPantryScientist.com

KitchenPantryScientist.com

KitchenPantryScientist.com

4. When the design is ready, roll it onto your egg like you’re rolling a bandage around an ankle. Try to keep in smooth and in a single layer. If it looks bad, try another one. You’ll get the hang of it!

KitchenPantryScientist.com

KitchenPantryScientist.com

5. Put the marbled egg on an egg carton to dry.

The science behind the fun: Nail polish is less dense than water and floats on top of it. It contains a solvent called acetate that evaporates very quickly into the air, drying out the polish.

Edible Egg Marbling (with Food Coloring and Whipped Cream)

 - by KitchenPantryScientist

Want to take egg-dying up a notch the easy way? Marbling eggs using whipped cream and food coloring is a great project for little ones and the results are downright gorgeous!

edible egg marbling

KitchenPantryScientist.com

Hint: Wear disposable glove to prevent your fingers from getting stained.

You’ll need:

-hard boiled eggs

-vinegar

-a shallow container

-cool whip or whipped cream

-food coloring (neon, if you can get it)

-a chopstick or toothpick

1. Soak eggs in vinegar for 5 minutes.

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You’ll see carbon dioxide bubbles forming on the eggs as the vinegar reacts with the calcium carbonate in the egg shells.

2. Spread and smooth a layer of whipped cream across the bottom of the container and drip food coloring all over the whipped cream.

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3. Swirl the drips into patterns using a toothpick or chopstick.

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KitchenPantryScientist.com

4. Remove eggs from vinegar, blot them with a paper towel and roll them through the food coloring. Put them on a plate to dry.

KitchenPantryScientist.com

KitchenPantryScientist.com

5. When the eggs are dry, wipe the excess whipped cream and color from the shells.

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KitchenPantryScientist.com

The science behind the fun: Food coloring is an acid dye, so the vinegar (acetic acid) helps it form chemical bonds with the egg shell, dying the egg.

Olive Oil Egg Marbling

 - by KitchenPantryScientist

It’s simple to make gorgeous marbled eggs using olive oil marbling. Simply dye your eggs with light coloed food coloring and then marble them with a darker color.

Oil-Marbled Eggs

KitchenPantryScientist.com

Hint: Wear gloves to avoid staining your fingers.

You’ll need:

-2 cups of warm water in a bowl

-hard boiled eggs

-olive oil

-vinegar

-food coloring (We used  Wilton Color Right food coloring: 2 drops blue mixed with one drop of yellow in about a cup of water to make robin’s egg colors, and brown for marbling.)

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1. Make base dye by adding a few Tbs. vinegar to two cups of water. To this, add a few drops of food coloring. Lighter colors work best for the base.

2. Dye the hard boiled eggs in the base color until they are the desired shade. Let them dry.

3. To a small bowl, add 1/2 cup water, a Tbs. of vinegar, darker food coloring, and 1/2 tsp olive oil. Add more oil if you want less dark color when you marble. Oil shouldn’t cover the entire surface.

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4. Swirl the oil with a toothpick or spoon and lower your egg into the water/oil mixture, swirling and spinning it. When you like the results, take it out and let it dry.

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5.When the egg is dry, remove the excess oil with a paper towel.

The science behind the fun: Food coloring is an acid dye, so the vinegar (acetic acid) helps it bond to the egg shell. Oil is less dense than water and floats on top. When you put the egg in the oil-colored water mixture, the oil coats part of the egg, preventing it from being stained.

 

Borax Alternative for Making Slime

 - by KitchenPantryScientist

If you prefer not to let your kids mix up slime using powdered detergent, contact lens solution containing boric acid makes a good Borax substitute, when combined with baking soda and glue. (Note: Most liquid laundry detergents in recipes for “Borax-free” slime contain Borax.)

What’s the science behind the fun? To make slime, you need a chemical called a crosslinker to make all of the glue molecules stick together. When you use contact lens solution, the boric acid in contact solution combines with baking soda to make borate, the same crosslinking solution that Borax contains.

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To make Borax powder-free slime, just add a pinch or two of baking soda per ounce of glue (around 1 tsp per bottle of clear glue), stir, add food coloring or glitter and then keep adding contact lens solution and stirring until the glue isn’t sticky any more. You can add water to the glue before adding the contact solution to change the consistency of the slime.

You can find more slime recipes here.

Slime versus Slime

 - by KitchenPantryScientist

A homemade slime craze is sweeping the nation, and glue is becoming a limited resource as stores are swarmed by school kids on a quest to make the perfect goo.

from Kitchen Science Lab for Kids (Quarry Books 2014)

from Kitchen Science Lab for Kids (Quarry Books 2014)

I’ve posted recipes and videos for slime-making on this website and included one in “Kitchen Science Lab for Kids.” For my most recent book, “Outdoor Science Lab for Kids,”  I invented a recipe for making slime that oozes from a bottle like a living thing.

From "Outdoor Science Lab for Kids" (Quarry Books 2016)

From “Outdoor Science Lab for Kids” (Quarry Books 2016)

But the other day, my 11-YO brought home a slime recipe featuring clear glue, baking soda, shaving cream and contact lens solution, and I was baffled. Which ingredient was the cross-linking chemical that would bind all of the glue molecules together into slime? I hadn’t had much luck using any cross-linker besides Borax laundry detergent.

Curiosity got the best of me, and a trip to Walgreens confirmed my suspicion that most contact lens solution contains boric acid, a cross-linking chemical related to Borax. In the glue aisle, I discovered a “Borax-free slime” recipe for slime made with Tide Free and Gentle. (Tide detergent does, in fact, contain the same chemical in Borax, so it’s not really Borax-free.)

A few days later, a friend called saying that the slime her kids were making with Borax and clear glue wasn’t turning out. That’s when I decided it was time for us to do some scientific sleuthing.

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From Kitchen Science Lab for Kids (Quarry Books 2014)

We tested two glues (clear glue and white school glue) with three cross-linking solutions (Borax laundry detergent, contact lens solution, and Tide Free and Gentle (which contains some Borax) to see how the end-products would differ.

Helpful hints: A bottle of glue contains 4 or 5 oz, which is a little more than half a cup. Mix glue with other ingredients BEFORE adding the cross-linker.  Keep slime away from toddlers, as ingredients may be harmful if consumed. Always wash your hands after playing with slime.

Here’s what we found:

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Traditional Borax Slime: Add equal parts glue and water (for example, one 5 oz bottle of glue+5 oz water.) Add glitter or food coloring. Dissolve a few spoonfuls of Borax in a cup of water to make a Borax solution. Add Borax solution to glue, a little at a time, until it no longer feels sticky. 

-White school glue works best for this recipe and the result is smooth slime that can be rolled into long snakes.

-Clear glue doesn’t work well with this recipe and produces brittle slime. Save clear glue for the two recipes below. 

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Puffy Slime: Add 5 oz glue to a large bowl. Stir in 1/2 tsp baking soda, 1/4 cup shaving cream and glitter or food coloring. Mix well. Add contact lens solution as a crosslinker and stir. Keep adding contact lens solution until your slime is no longer sticky and knead slime until it has the desired consistency. 

-White school glue works well with this recipe and results in a puffier, firmer product than clear glue. The slime has a strong shaving cream smell. 

-Clear glue works well for this project and produces nice, smooth puffy slime that smells like shaving cream.

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Tide Detergent Slime: Add 5 oz glue to a large bowl. Stir in 5 oz water and some glitter or food coloring. Add 1/4 cup of Tide Free and Clear laundry detergent. Mix well with a spoon and then hands to the desired consistency. 

-White school glue works well with this recipe and the soap in the detergent makes tiny bubbles in the slime. 

-Clear glue works well for this project and makes great , smooth slime that’s puffy from the soap in the detergent.

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Try adding cornstarch, lotion, or anything else you can think of to perfect your recipe.

What are you waiting for? Go make some slime!

The Science Behind the Fun:polymer is a long chain of repeating molecules, kind of like a string of pearls. The polymer in school glue is called polyvinyl acetate. Borax solution (sodium tetraborate) and boric acid (combined with baking soda to make borate), are cross-linking substances that make the polymer chains in glue stick together.  As more and more chains stick together, they can’t move around and the solution gets thicker and thicker.  Eventually, all the chains are bound together and no more Borax or boric acid solution can be incorporated into the slime.

 

Graphite Circuits

 - by KitchenPantryScientist

Electrons (negatively charged particles) can flow through substances called conductors.

Graphite, used to make pencil lead, among other things, is a conductor and can be used to make a simple circuit on paper. A circuit is just a path for electrical current.

You have to do this experiment with a graphite pencil, rather than the kind you use at school, but you can pick them up at most art supply stores. You’ll also need a few small LED bulbs, 2 wires with alligator clips on either end, and a 9 volt battery.

Adult supervision recommended.

  1. Make a thick, black rectangle using a graphite pencil. We used a #9 graphite crayon.
  2. Hook the two wires up to the battery terminals.
  3. Clip the wire attached to the positive battery terminal to one wire of an LED bulb. (Don’t test it on the battery, or you may blow it out.)

IMG_58434. Touch the un-attached LED wire to the other (left) side of the graphite bar.

IMG_58445.Touch the alligator clip attached to the negative battery terminal to the right side of the graphite bar you drew.

6.If it doesn’t light, switch the positive alligator clip to the other wire of the LED bulb and try it again.

7. Move negative clip closer to the bulb. It should get brighter as you decrease the distance.

 

Lemon Batteries

 - by KitchenPantryScientist

To make a battery, you need two oppositely charged electrodes (materials that pass electrical current from one thing to another) and an electrolyte (a liquid that allows charged atoms to travel through it.)

If you stick a zinc (galvanized) nail and a copper wire side by side into a lemon, but not touching each other, they act as electrodes. The lemon juice acts as the electrolyte.

A chemical reactions occurs between the zinc electrode and the acidic lemon juice, resulting in a second chemical reaction at the copper electrode. If you attach the two electrodes to a metal wire, electrons from the chemical reaction will flow through the wire from the zinc to the copper, creating an electric current.  We used a tool called a mutimeter to connect the two electrodes and measure the current flowing through the wire.

To make a lemon battery, push a zinc nail and a piece of copper into a lemon, side by side, but not touching. You can use a copper wire or a penny.

Touch the two ends of a multimeter to each of the electrodes to see how much current you’re generating. (See image below.)

Lemons with zinc and copper electrodes

Lemons with zinc and copper electrodes.

Testing current produced by a single lemon using a multimeter.

Testing current produced by a single lemon using a multimeter.

 

Test how changing the distance between the two electrodes changes the current. What else could you try?

Electroscopes and Static Electricity

 - by KitchenPantryScientist

Repost from Dec.19th, 2010 (Photos from Kitchen Science Lab for Kids, Quarry Books 2014)

Have you ever gotten a shock from a doorknob after shuffling across a carpet? The term “static electricity” refers to the build-up of a positive or negative electrical charge on the surface of an object.  In this case, the charged object is your body.  You feel an electric shock as the charge you’ve collected from the carpet jumps from your hand to the metal doorknob.

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Tiny particles called electrons have negative charges and can jump from object to object. When you rub a balloon on your hair, or a comb through it, many of these electrons are stripped from your hair and move to the balloon or comb giving it a negative charge (and often leaving your hair all positively charged and standing up as the strands try to avoid each other.)

The negatively charged balloon or comb then makes a great tool for making electrons jump around!

You can easily make a contraption called an electroscope using:

-a jar

-some thin aluminum foil or mylar (the shiny stuff balloons and candy wrappers are made from)

-cardboard

-a nail

-tape

-a balloon or comb.

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from Kitchen Science Lab for Kids (Quarry Books 2014)

  1. Cut the cardboard to fit over the mouth of the jar, poke the nail through the cardboard, tape on two long, thin strips of foil or mylar (see photo) and place the whole thing in the jar so the foil strips hang down, touching each other.

 

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Electroscope from Kitchen Science Lab for Kids (Quarry Books 2014)

 

2. Charge your balloon or comb by rubbing it on your hair or clothing to give it a negative charge.  Bring the charged object close to the nail head.  You don’t      even have to touch it!

From Kitchen Science Lab for Kids (Quarry Books 2014)

From Kitchen Science Lab for Kids (Quarry Books 2014)

 

What happened? Some negatively-charged electrons jump from the comb to the nail and into the strips of foil.  The negative charge on the comb will push electrons (which are also negatively charged) down to the foil/mylar and give both strips a negative charge. The two strips try to move away from one another as the like charges repelled each other.

What happens when you make the strips out of different materials like paper?  Are there other charged objects you can use to make your foil strips “dance”?

You can also bend a thin stream of water from the faucet by holding your charged comb next to it.  The water is uncharged and is pulled toward the negative charge of the comb.

Try making small pieces of tissue paper float or dance by holding a charged comb or balloon next to them!  We filled an empty soda bottle with tiny pieces of foil and made them jump around with a charged comb held close to the bottle.

 

Permanent Marker Tie Dye (Color and Chemistry)

 - by KitchenPantryScientist

(Re-post from April 14, 2016)

I love traditional tie-dye, but it’s fun to do this experiment that uses permanent markers and rubbing alcohol to make bright, gorgeous designs that mimic tie-dye, more easily, and with less mess.

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This experiment was created by Bob Becker, a chemistry and AP chemistry teacher at Kirkwood High School in Kirkwood, MO.  (To find a few of the original experiments I invented, check out Frankenworms, Sugar Cube Fizz Bombs, Homemade Window StickiesFoaming Slimeand Cornstarch Frescos.)

Here’s a video from my YouTube channel on how to do this experiment, so kids can “watch and do.”

To play with permanent marker tie dye, you’ll need:

-permanent markers (like Sharpies) 

-cotton items to decorate, like tee-shirts, socks, or dish towels

-rubbing alcohol (isopropanol)*Read warning labels. Parental supervision is required, since rubbing alcohol is poisonous if swallowed. Do this experiment in a well-ventilated area, and do not expose your artwork to heat until is is COMPLETELY dry, since rubbing alcohol and its fumes are flammable.

-rubber bands

-eye droppers

-containers like plastic cups or jars

To make your designs, stretch the cotton over the mouth of a jar or cup and secure it with rubber bands. (See video above.)

Use permanent markers to make several dime-sized dots of different colors on the stretched cotton.

Slowly drip rubbing alcohol onto the spots of color until the alcohol starts to soak outward, carrying the ink with it.

Allow your design to dry overnight. When completely dry, hang your shirt in the sun, or put it in the dryer for 15 minutes to set the color. Wash separately from other clothes, just in case!

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The Science Behind the Fun: Pigments are molecules that give things color. The pigments in permanent markers are trapped in ink compounds that are insoluable in water, which means that they won’t dissolve in water. However, if you add a solvent, like rubbing alcohol, or isopropanol, to permanent markers, it dissolves the ink. As the alcohol moves through the cloth you are decorating, it carries the pigments along with it. Small pigment molecules move faster than big ones, so the colors sometimes separate into their different color components as they move through the cloth. The alcohol evaporates into the air, leaving the ink in the fabric, and since it is still insoluable in water, it won’t come out when you wash it. 

Enrichment: What happens if you draw lines, concentric circles or different shapes on your designs? Can you layer colors and watch them separate? What if you add rubbing alcohol next to the color, instead of directly on it? How many drops of alcohol do you have to add to a dime-sized color spot before it starts to expand?