Category Archives: Sick Science Experiments

Create a Rainbow in a Bag – Pinch and Mix Color Mixing

By Blog Editor Susan Wells

I’m occasionally asked by teachers and school groups to bring in a few hands-on science experiments for a class. One of my all-time favorite go -to activity is color mixing with Pinch and Mix goo. Steve Spangler Science sells and all-in-one Pinch and Mix Kit for 30 students or a smaller group. You can also use gel cake frosting if you want to do it yourself.

Start this activity with a literature connection by reading the book Mouse Paint by Ellen Stoll Walsh. Mouse Paint is a delightful story about three white mice who discover jars of red, yellow, and blue paint. Creativity ensues as the mice explore what happens when they begin to play in the puddles of paint. Wondrously, the three primary colors they began with become secondary colors as they play.

Now it is your turn to delight and discover. Discuss what the mice found and what happened after they were coated in one color paint and messed about in another color. Then make your own color connections by pretending you are little mice mixing the colors in your zipper-lock bag!

Squeeze 1 to 2 tablespoons of each color of goo into the bag. It’s best if you place one color in each corner and one in the middle. Then gently squeeze air out of the bag and seal it. Pinch and mix the colors together by blending the primary into secondary colors. The bag will start to take on a soft, stained glass look.

Hold it up to a light or a sunny window.

Some kids will gently and carefully blend their colors, but most will grab and squish the bag until the colors turn army green, grey and putrid purple. Don’t worry about a failed activity; the kids will still find beauty and discovery in their crazy-made colors.

Make sure you keep a Sharpie nearby, because the kids will want to bring home their creations.

For more on this fun and colorful activity, visit the Pinch and Mix Experiment page.

Teaching Student Leadership Lessons Through Needles and Piercings

Stand back and watch as I pull a needle through a balloon without popping it.

This trick is a magicians’ favorite. They can mystify an audience by putting a needle through a balloon and pulling through a ribbon without popping it. The demonstration is mysterious until you learn a little stress-related science.

When a balloon is inflated, the middle is under a lot of stress and pressure from the air inside. The top and bottom are not stretched as far or put under as much pressure. To illustrate this – color dots all over a deflated balloon. Then blow it up and look at the dots. The dots in the center of the balloon will be stretched and thin, while the dots on the ends won’t be stretched as far.

To use this demonstration as a student leadership lesson, use the balloon as an example of a real world problem. If you approach  a volatile situation at the most tense and stressed out part, the balloon or the situation may pop. But if you cautiously approach it from the strongest point, you may just get through.

For the complete experiment and science behind it, visit the Skewer Through the Balloon experiment page.

The Science Behind Composting – Nourish the Planet on Earth Day

By Blog Editor Susan Wells

Spring time means getting out and enjoying the sun, watching the trees bloom and cleaning out those flower beds and garden patches and filling them with flowers and plants. Before you start clearing out the dead of winter and putting plants in the ground, get a little compost going.

Compost is the single most important supplement you can give your garden soil.

Compost creates nutrient-rich humus – a natural fertilizer. This super charges plant growth and helps keep moisture in the soil. Your water bill can be reduced by 20%.  It also adds microscopic organisms that works to aerate the soil, break down organic materials and fight off plant disease and insects.

By composting your organic kitchen waste, your trash will be lighter and your footprint smaller. About 30% of household trash is compostable materials.

Materials Needed

  • Carbon materials (The brown material) - newspaper, cardboard (not shiny), paper towel and toilet paper rolls, wool, cotton, dryer lint (from natural fibers only), egg shells, sawdust (lightly to avoid clumps), tea bags, shredded brown paper bags, conifer needles, bits of wood, hay, peet moss, coffee filters, stalks from perennial plants, end of season annual plants, branches, dry leaves, egg cartons made from paper, paper (not shiny).
  • Nitrogen materials (the green material) - fruit or vegetable peels and cores, coffee grounds, all non-meat food scraps, manures (not pet waste), lawn clippings, green leaves, seasonal thinnings from the vegetable or flower garden.
  • Do not put bones, fish scraps, dairy, fat (they will attract pests), plants treated with pesticide, perennial weeds or diseased plants. Also avoid black walnut leaves.
  • Water
  • Air
  • Time

Composting Techniques

  • There are several varieties of rotating composting tumblers on the market. They are expensive but don’t require a lot of work to rotate the material.
  • Make your own composter. Purchase a plastic bin or garbage can and drill some holes in the top and sides to allow air to flow. Secure a cedar plank inside a garbage can and roll it to mix materials.
  • Open air compost pile on the bare ground. This allows worms and other organisms to easily get into your pile and aerate.

Build a Compost Pile

  • Start with sticks or straw on the bottom to help with drainage and aeration. Then place carbon and nitrogen materials. suggests you have 2/3 carbon and 1/3 nitrogen on a 3′x3′x3′ pile.
  • Put a 4-6″ layer of mixed carbon materials on top of the sticks or straw.
  • Add a 2-3″ layer of mixed nitrogen and one handful of garden soil.
  • Mix the layers together and water until the pile feels as wet as a wrung out sponge.
  • Continue to add layers, mix and water until pile reaches about 3′ high.
  • If compost pile is on the ground, cover with black plastic, wood or carpet scraps. This will hold in the heat and moisture – two essential ingredients for great compost.
  • Do not allow the compost to get soaked or overwatered. The pile should be moist.

Maintaining the Pile

  • Rotate the pile once a week. Turn materials from top to bottom.
  • Add a little water if compost isn’t moist.
  • Add food scraps to the middle of the pile and cover with carbon material.

Mature Compost

  • The compost is finished when it looks like dark potting soil and is reduced by half its original size.
  • Contents are not recognizable.

 How to Use It

  • Add a few handfuls of compost into the top 4″ of the soil when planting plants. It can also be added lightly as a top-dressing around plants several times during the season. Compost should only be 25% of the potting soil around a plant, because it is so full of rich nutrients.

Don’t stress about getting it all exactly right. Composting is a natural process and this just speeds it all up. As long as you have all 5 of the main components, you will get nutrient-filled compost for your plants this spring and summer.

Another great idea is to move your compost pile every season and then plant in last year’s location. The soil will be perfect for growing vegetables and beautiful flowers.

Denver offers composting classes and a lot of information on Urban gardening. They also have information on Vermicomposting (using a specific type of worm to compost). offers a lot of information, trouble shooting and bins. Click the link for a chart of compostable materials, whether or not they are carbon or nitrogen and how to use them.

Thank you to both and for help in pulling together this post.

The Science Behind Clouds – On a Cloudy Day You Can See Weather

Have you ever wondered how clouds form? We all learn the water cycle in school – water falls from the clouds in the form of rain or snow and collects on the ground. The water on the ground heats up and turns to vapor and the vapor travels up into the atmosphere and creates clouds.

But how do those clouds form? Here’s an experiment that demonstrates how the water molecules join together and form a cloud.

Before you start on your own cloud, let’s learn a little more about clouds.

A cloud is a lot of droplets of water and or ice crystals, depending on the temperature. The droplets float in the air molecules.

Even though we don’t see them, water molecules are in the air all around us. These airborne water molecules are called water vapor. When the molecules are bouncing around in the atmosphere, they don’t normally stick together.

Clouds on Earth form when warm air rises and its pressure is reduced. The air expands and cools, and clouds form as the temperature drops below the dew point. In other words, cold air cannot hold as much water vapor as warm air. Invisible particles in the air in the form of pollution, smoke, dust or even tiny particles of dirt help form a nucleus on which the water molecules can attach. When these droplets come together, they form a cloud.

Why do clouds float instead of sinking to the earth? The water droplets in a cloud are heated up by the sun. The cloud and the water vapor inside are warmer than the air around it. Warm air rises, cold air sinks. How much water vapor, temperatures at different heights, wind and other air masses determine what altitude the clouds are formed.

Try this simple and popular Colorful Rain Cloud in a Jar activity -


  • Clear jar
  • Water (any temperature)
  • Shaving cream
  • Cup of water with a little food coloring
  • Pipette (or spoon)
  • Food coloring
  • Fill jar about 3/4 full with water
  • Spray shaving cream to cover top of water completely.
  • Drip water on top of the shaving cream using pipette.
  • Drip food coloring on top of the shaving cream.
When a rain cloud gets so full of water or mass, the water has to go somewhere and will break through the cloud and start to fall to the ground. As you pour or drip the water over the shaving cream cloud, the water will start to break through just a little bit. Observe your cloud as it gains mass and changes in composition. As the water breaks through, drip food coloring on top of the cloud.
Questions and Answers to Popular Cloud Questions -
1. Why are clouds white? 
The water droplets and ice crystals that make up clouds, scatter the light rays and reflect white light. Sunlight is made up of all colors. When all colors of the light spectrum mix, it creates white light. This is the opposite of paints or physical colors, which blend to black. The clouds reflect all of the colors evenly, showing white.
2. Why are storm clouds grey? 
When the clouds get thick or high in the sky, the light does not make it all the way through to reflect back out, making the cloud appear grey. When many clouds are together, they can also cast shadows on other clouds, causing the clouds to look grey.
3. How do clouds move?
The clouds and the storms they form move in the air currents, wind and jet stream.

Here’s another popular cloud activity – Cloud in a Jar
This activity requires adult help.  


  • Jar
  • Hot Water
  • Ice
  • Plate or jar lid
  • Matches
  • Fill jar about half way full with very hot water. (Have an adult help with this part)
  • Cover the jar with the plate or lid and place ice on top.
  • Let it sit for a few minutes – you will start to see a cloud form. Watch the convection currents as the hot air rises to meet the cold air and then sinks again.
  • Light a match (bring your adult helper back in for this part), let it burn down for a few seconds.
  • Blow out the match and place it between the jar mouth and plate.
  • The cloud and the air currents will be more visible.
  • Lift off the plate and watch the cloud disperse.
  • Try it again!

Additional Resources: