Category:Physics Experiments’

Give the Gift of #STEM: Homemade Science Kit

 - by KitchenPantryScientist

Image from “Kitchen Science Lab for Kids” (Quarry Books 2014)

There are few gifts more fun than a homemade science kit. Give a kid a bottle of vinegar and a box of baking soda and you’ll make their day. Throw in a bottle of Diet Coke and some Mentos mints, and you may be their favorite person ever. Make a kit for your kids or grand kids. Make one for your favorite niece or nephew. Encourage kids to make kits for friends and siblings.

Here are some ideas for items to include in your kit.I’ve highlighted links to the experiments on my website (just click on the blue experiment name) in case you want to print out directions to add to your kit. You can also find these experiments on my Kitchen Pantry Scientist YouTube channel!

-composition book: Makes a great science notebook to draw, record, and tape photos of experiments into.
-clear plastic cups to use as test tubes and beakers
-measuring spoons and cups 
-school glue (white or clear) for making Mad Scientist’s Slime
-contact lens solution for making Borax-free Slime
-gummy worms to transform into Frankenworms
-baking soda: Can be used for a number of experiments like fizzy balloons, magic potion . Or just mix with vinegar to make carbon dioxide bubbles.
-vinegar Great for fizzy balloons , alien monster eggs and magic potion.
-balloons for fizzy balloons.
-dry yeast for yeast balloons.
-white coffee filters: can be used for magic marker chromatography, in place of a paper bag for a coffee-filter volcano or making red cabbage litmus paper.
-cornstarch:Lets you play with Cornstarch Goo, a non-newtonian fluid. Here’s the video.
-marshmallows with rubber bands and prescription bottle rings you have around the house can be used to make marshmallow catapults. My kids used theirs to make their own Angry Birds game.
-Knox gelatin and beef bouillon cubes can be used to make petri plates for culturing microbes from around the house. You can also use the gelatin for cool osmosis experiments!
-food coloring Helps you learn about surface tension by making Tie Dye Milk. Here’s the video. You can also easily make colorful sugar-water gradients that illustrate liquid density!
-Mentos mints will make a Mentos geyser when combined with a 2L bottle of Diet Coke.
-drinking straws are great for NASA soda straw rockets and a carbon dioxide experiment.

To take it up a notch, throw in a copy of one of my book! You can find them on Amazon, Barnes and Noble and anywhere else books are sold! 

Happy Experimenting! 

 

Think #STEAM! Homemade Holiday Window Stickies

 - by KitchenPantryScientist

 

Gelatin is the substance that makes Jell-O jiggle. See what happens when food coloring molecules move, or DIFFUSE through Jell-O.

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This creative science experiment that my kids and I invented lets you play with floatation physics by sprinkling glitter on melted gelatin, watch colorful dyes diffuse to create patterns and then use cookie cutters to punch out sticky window decorations.  Water will evaporate from the gelatin, leaving you with paper-thin “stained glass” shapes.

You’ll need

-plain, unflavored gelatin from the grocery store or Target

-food coloring

a drinking straw

-water

-a ruler

-glitter

*You can use the recipe below for two pans around 8×12 inches, or use large, rimmed cookie sheets for your gelatin. For a single pan, cut the recipe in half.

Step 1. Add 6 packs of plain, unflavored gelatin (1 oz or 28 gm) to 4 cups of boiling water. Stir well until all the gelatin has dissolved and remove bubbles with a spoon.

Step 2. Allow gelatin to cool to a kid-safe temperature. Pour the liquid gelatin into two large pans so it’s around 1-1.5 cm deep. It doesn’t have to be exact.

Step 3. Sprinkle glitter on the gelatin in one pan.  What happens?
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Step 4. Allow the gelatin to harden in both pans.

Step 5. In the pan with no glitter, use a straw to create holes in the gelatin, a few cm apart, scattered across the surface. It works best to poke a straw straight into the gelatin, but not all the way to the bottom. Spin the straw and remove it. Then, use a toothpick or skewer to pull out the gelatin plug you’ve created. This will leave a perfect hole for the food coloring. Very young children may need help.
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Step 6. Add a drop of food coloring to each hole in the gelatin.
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Step 7. Let the gelatin pans sit for 24 hours. Every so often, use a ruler to measure the circle of food coloring molecules as they diffuse (move) into the gelatin around them (read about diffusion at the bottom of this post.)  How many cm per hour is the color diffusing?  Do some colors diffuse faster than others? If you put one pan in the refrigerator and an identical one at room temperature, does the food coloring diffuse at the same rate?

Step 8. When the food coloring has made colorful circles in the gelatin, use cookie cutters to cut shapes from both pans of gelatin (glitter and food coloring), carefully remove them from the pan with a spatula or your fingers, and use them to decorate a window. (Ask a parent first, since some glitter may find its way to the floor!) Don’t get frustrated if they break, since you can stick them back together on the window.
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Step 9. Observe your window jellies each day to see what happens when the water evaporates from the gelatin.
IMG_3688When they’re dry, peel them off the window. Are they thinner than when you started? Why? Can you re-hydrate them by soaking the dried shapes in water?
IMG_3691The Science Behind the Fun:

Imagine half a box filled with red balls and the other half filled with yellow ones.  If you set the box on something that vibrates, the balls will move around randomly, until the red and yellow balls are evenly mixed up.

Scientists call this process, when molecules move from areas of high concentration, where there are lots of other similar molecules, to areas of low concentration, where there are fewer similar molecules DIFFUSION. When the molecules are evenly spread throughout the space, it is called EQUILIBRIUM. 

Lots of things can affect how fast molecules diffuse, including temperature.  When molecules are heated up, they vibrate faster and move around faster, which helps them reach equilibrium more quickly than they would if it were cold. Diffusion takes place in gases like air, liquids like water, and even solids (semiconductors for computers are made by diffusing elements into one another.)

Think about the way pollutants move from one place to another through air, water and even soil. Or consider how bacteria are able to take up the substances they need to thrive. Your body has to transfer oxygen, carbon dioxide and water by processes involving diffusion as well.

Why does glitter float on gelatin? An object’s density and it’s shape help determine its buoyancy, or whether it will float or sink. Density is an object’s mass (loosely defined as its weight) divided by its volume (how much space it takes up.) A famous scientist named Archimedes discovered that any floating object displaces its own weight of fluid. Boats have to be designed in shapes that will displace, or push, at least as much water as they weigh in order to float.

For example, a 100 pound block of metal won’t move much water out of the way, and sinks fast since it’s denser than water. However , a 100 pound block of metal reshaped into a boat pushes more water out of the way and will float if you design it well!

What is the shape of your glitter? Does it float or sink in the gelatin?

Here’s a video I made for KidScience app that demonstrates how to make window gellies

Credit: My 11 YO daughter came up with the brilliant idea to stick this experiment on windows. I was just going to dry out the gelatin shapes to make ornaments. Kids are often way more creative than adults!

Rubber Band Car

 - by KitchenPantryScientist

It’s fun to make a rubber-band powered car from cardboard, straws, and wooden skewers!

You’ll need:

-heavy cardboard

-rubber bands

-glue (a glue gun works best)

-a plastic straw

-wooden skewers

-a CD (or a compass)

-a ruler

-screwdriverCu

-pipe cleaner (optional)

Hints: Parental supervision recommended for hot glue gun use.

Here’s what you’ll be building:

Rubber Band Car kitchenpantryscientist.com

What to do:

  1. Wrap cardboard around a large spice bottle so you can see how it bends. Cut a piece of cardboard about 9 inches (22cm) long to wrap around the bottle. Trim off the excess cardboard and tape it to create a tube.

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  2. Trace a CD or use a compass to make 8 circles that are around 4 and 1/2 inches (12 cm) in diameter. Use a ruler to make a square around each circle and then diagonal lines to mark the center of each circle. Cut them out and glue two circles together until you have four wheels. Use skewers to poke holes through the center of each wheel.

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  3. Poke skewers through each end of the cardboard tube, about 1 and 1/2 inches (4 cm) from the end of each tube. Make sure that the skewers are parallel and that they line up when you look through the end of the tube.

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    kitchenpantryscientist.com

  4. Use a screwdriver to make the holes larger.

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  5. Cut 4 pieces off of a straw that are about 1/2 inch (1.5cm) long. Glue them to the outside of each hole in the tube. Use a skewer to help align them. The skewer should spin freely.

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  6. One at a time, put wheels on the skewers and glue the OUTSIDE of the wheel to the skewer. Make sure that the wheels are parallel to the car, and to each other as they dry. Cut off excess skewer.

    kitchenpantryscientist.com

    kitchenpantryscientist.com

  7. Poke a skewer down the center of one end of the car, parallel to the wheels so that it’s sticking out about 1 inch (3 cm.) See image above.
  8. Decorate the car!
  9. Tie three thin rubber bands together and hook them over the skewer that’s sticking out. If you have a pipe cleaner or wire, hook it onto the other end of the rubber bands. Drop the rubber bands down through the center of the tube.

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  10. Grab the rubber bands from the end opposite where they are attached to the car. Remove the pipe cleaner hook and wind them around the skewer to create tension in the rubber bands. Wind them until they’re tight.

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  11. Set the car down and let the wheels start to spin to see what direction the car will go. When you’re ready, let go!
  12. Measure how far the car traveled.

Enrichment: How can you make the car go faster or farther. Try using different kinds and numbers of rubber bands. How could you redesign the car to make it work better?

The Science Behind the Fun:

In this experiment, you use your body’s energy to twist rubber bands around the wooden skewer axle of a cardboard car. The energy is stored as elastic energy in the tightly-stretched rubber bands. When you let the car go, the rubber bands apply enough force on the axle to turn the wheels on the car and elastic energy is transformed into the energy of motion, which is called kinetic energy.

 

Elemental Science: Gallium

 - by KitchenPantryScientist

Gallium is a soft metal related to other metals in Group 13 of the periodic table, including aluminum. It doesn’t exist as a free element in nature, but can be purified from other metallic ores, like zinc. Each gallium atom has 31 protons in its nucleus, so its atomic number is 31.

You’ll find it around you in thermometers, semiconductors, and even some LED lights, and one property that makes it so cool is that it melts from solid to liquid at low temperatures (around 85.6 degrees F or 29.8 degrees C.) This makes it easy to play with the liquid metal simply by melting it in a glass of hot water, or in the palm of your hand.

You can see the crystal structure in the side of the gallium “Lego” we created in play dough! KitchenPantryScientist.com

*Not for small children! Wearing gloves and safety goggles is recommended when observing gallium. Although is is fairly safe, gallium will coat hands with a lead-like substance. (Wash with soap and water to remove.) Gallium can also damage other metals, so keep it away from jewelry, like rings. I always recommend doing your research, as well as checking out the MSDS (Material Data Safety Sheet) of a new substance before using it to know what precautions to take.

We ordered 99.99% pure gallium on Amazon. It arrived in plastic tubes,in crystal form, but by placing the tubes in hot tap water, it melted easily. Eye droppers work well for moving the melted metal around. I’d recommend using a rimmed paper plate to contain the mess.

Try imprinting a Lego or toy car in play dough and pouring the molten gallium into the imprint. When it solidifies, you’ll have a cast of the item you imprinted! (It takes a while.) Gallium coats glass to create mirrored surfaces, so you can pour some into a small jar and use it to coat the sides. If you leave some in a puddle on the bottom of an upside-down jar, you can watch crystals form.

In other words, it’s pretty awesome!

Science Light

 - by KitchenPantryScientist

Here’s a fun optics experiment, based on one created in 1842 by Jean-Daniel Colladon, that you can do at home using a laser pointer and a bottle of water.

Parental supervision required. (Eye protection recommended for kids.) Never shine a laser pointer at or near eyes, as it can cause blindness.

Skullsinthestars.com has a well-written, detailed explanation of how light can be reflected in a transparent medium, like water.

 

Floating Ping Pong Balls

 - by KitchenPantryScientist

This experiment is so awesome that our balloon-popping dog Heidi had to get in on the action! Try it, and you’ll see how much fun it is to play with the forces of physics using a blow drier and a ping pong ball or balloon.

Newton’s third law tells us that for every action, there is an equal and opposite reaction. As the air pushes up on the ball, the ball pushes back down on the air. Other forces are at work too, as pressure differences in the air column help the ball stay in the middle of the air flow.

Weather Science

 - by KitchenPantryScientist

It’s fun to track the weather, and you can create some cool meteorology instruments using stuff you have around the house. Here’s a great post by NOAA (The National Oceanic and Atmospheric Association) on how to make your own weather station.

It’s also fun and easy to do this cool convection current experiment, using warm and cold water to explore how air moves in Earth’s atmosphere.

Convection Experiment (kitchenpantryscientist.com)

To see how cold fronts move under warm fronts, you’ll need ice cube trays, water, blue and red food coloring and a clear container.

  1. Add water to an ice cube tray and add a few drops of blue food coloring to the water in each cube space. Freeze.
  2. Fill a clear container with room temperature water.
  3. Place one or two blue ice cube or two at one end of the container, and a few drops of red food coloring at the other end.
  4. Observe what happens.

The Science Behind the Fun:

Cold water(blue) is more dense than warm water and forces warmer water (red) to move up and over it.

This is similar to the way warm air is forced up when it collides with masses of cold air in the atmosphere. Warm air carries energy, and when there’s lots of moisture in the air, these collisions often result in thunderstorms.

 

Homemade Tie-Dye Fidget Spinner

 - by KitchenPantryScientist

Homemade Spinner with Tie-Dye Edges (KitchenPantryScientist.com)

Make a super-cool spinning toy using skateboard bearings, super glue and a little physics. Customize your design with a marker tie-dyed shoelace.

Warning: Not for recommended for kids under 5. Use adult supervision for super glue, sharp points, rubbing alcohol and glue gun.

You’ll need:

-4 skateboard bearings (available online or at skateboard stores)
-superglue or Krazy Glue
-a white shoelace
-permanent markers, like Sharpies
-rubbing alcohol (isopropanol)
-a glue gun

KitchenPantryScientist.com

1. Use a sharp point to remove the cover from one of the bearings so that you can see the ball bearings inside. (See image above.)
2. Cut a piece of paper 6cm x 6cm and draw an X from corner to corner.
3. Center the bearing with the cover removed in the middle of the X. Then, center the other 3 bearings around the one in the middle so that they’re evenly spaced. You can use a ruler to check spacing. (See image below.)

KitchenPantryScientist.com

4. Add a single drop of super glue to the junction between each bearing to connect them. If you add too much, the spinner will stick to the paper. *Be careful not to get any glue onto the moving parts of the bearings.

KitchenPantryScientist.com

5. When the glue is dry, carefully turn the spinner over and place another drop of glue at each junction.

6. When the glue is dry, prop the spinner up on its side and add glue to the junctions on the sides. (See image below.) Repeat on each side.

KitchenPantryScientist.com

7. While the spinner glue is drying, make dots of permanent marker on the shoelace. In a well-ventilated area, suspend the shoelace over a tray or colander and drip rubbing alcohol onto it to make the colors run together. (See image.) Let it dry completely.

KitchenPantryScientist.com

8. Use the glue gun to attach the shoelace to the outside edges of the spinner. Fill in gaps between the lace and bearings with hot glue.

KitchenPantryScientist.com

9. Spin away!

The Science Behind the Fun:

If you look closely at a skateboard bearing there are only a few ball bearings connecting the center and the outside part that spins. This means that there’s very little friction, or rubbing, between the parts. If you spin the toy around the center bearing, that bearing is called the axis of rotation.

The three bearings on the outside of the spinner provide the rotating mass that gives the toy a property called angular momentum, which keeps it spinning until the frictional force from the ball bearings in the center slows it down.

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.

Bristlebots

 - by KitchenPantryScientist

With a brush, some batteries, a small motor and a few wires, it’s easy to create a robot that spins, bumps and buzzes around on any smooth surface.

You’ll need:

-a small brush, like a vegetable brush or a cleaning brush

-two AA batteries

battery holder for 2 AA batteries (optional)

-insulated wire

-a small toy motor with lead wires and pencil eraser or small rubber stopper (or vibrating motor)

battery clip (optional)

-zip ties (optional)

-electrical tape or duct tape

Bristlebot-KitchenPantryScientist.com

Make your bristlebot!

  1. Attach the motor to one end of the top of the brush. If it’s not a vibrating motor, stick a eraser or rubber stopper onto the spinning post to make it vibrate. Use a zip tie or duct tape to secure it. Make sure the spinning parts can rotate freely.

    Attach motor- KitchenPantryScientist.com

  2. Attach the battery holder to the top of the brush near the motor.

    Attach batteries- KitchenPantryScientist.com

  3. Insert batteries in motor.
  4. Twist wires around the motor terminals and secure with tape. (These may be the wires on the battery clip, if you have one.)

    Connect battery clip- KitchenPantryScientist.com

  5. To start the motor, attach wires directly to the battery terminals, or to the battery clip and snap it onto the batteries.

    Bristlebot- KitchenPantryScientist.com

  6. Place your robot on a smooth surface to see what happens.

Enrichment: Try different brush shapes, sizes and angles to see how they move. Does your robot spin in the same direction as the motor, or the opposite direction?

The Science Behind the Fun: In this experiment, you complete a battery-powered electrical circuit to spin a vibrating motor. The vibrations traveling through the bristles of the brush move your robot around on the floor.

 

 

 

 

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.