1. Ice Spikes

Have you ever seen bumps or spikes come up from the ice cubes in your ice cube tray? SnowCrystals.com has a great discussion of ice spikes, how they form and how to grow some of your own. For more pictures and a movie, try Spikes on Ice Cubes.

2. Ice cube rescues

Give your child(ren) a challenge to “rescue” ice cubes floating in a glass of water with only a piece of string and some salt. Then watch this video to see how it is done.

3. Freezing and thawing water

Freeze water in various-sized containers and then set the ice “sculptures” out to thaw. (Set them in in deep bowl indoors or outside on a sidewalk or patio where a little melt water won’t matter.) Time how long it takes various sizes and shapes to melt with a watch or clock. Does size or shape influence melting time? How?

Try freezing a water-filled water balloon (set in a bowl first). Once it is frozen, what happens when you toss it? What happens when you freeze a balloon filled with air in a bowl of water?

4. Floating and sinking

Create an ice cube boat and float it to emphasize that ice is less dense than water.

Gather:

• ice cube tray
• cold water
• pie plate or shallow bowl
• plastic wrap
• toothpicks
• triangle of paper
• clay (optional)

Fill the ice cube tray with water. Cover the tray with a tight layer of plastic wrap, which will hold up the toothpicks. Stick a toothpick in the center of each cube, enough so that there is a least one for each child. When the ice cubes are frozen, remove from the tray. Insert a small triangle of colored paper on each toothpick to make a sail, and float the ice cubes in a bowl of cold water (the colder the better). Do the boats float? Do they stay upright? If not, try adding some clay to the bottom until the ice cubes are balanced. (This may be difficult at first, if the oily clay doesn’t stick to the wet ice. I found it did work with patience.)

5. Moving on to dry ice

Dry ice (frozen carbon dioxide) is available at many grocery stores. Just remember that it is much colder than regular ice and will require special handling. Always use gloves, and tongs are a good idea too. Never put dry ice in a swimming pool!

See this Steve Spangler video for some ideas and handling suggestions.

Ice is so much fun to experiment with in the summer. Let me know if you have any other experiments to do with ice or activity tips.

For more information, try these books:

and these related subjects:

Ice Scientist: Careers in the Frozen Antarctic (Wild Science Careers) by Sara L. Latta

Pioneering Frozen Worlds by Sandra Markle

Boats!

Children are fascinated by boats and floating. You can do a lot of interesting science projects with boats, starting with some basic questions: How can huge pieces of heavy metal float? How are boats propelled? Can you really make a boat out of paper?

We already have covered some floating and boat topics in previous posts.

Why Things Float contains some experiments on floating and sinking.

The How long can a paper boat float? challenge, with the early results for paper boats challenge.
The yellow legal pad boats lasted five days.

The Bathtub Buoyancy Challenge asked kids to find ways to propel boats across a bathtub without using their hands or electrical motors. The Bathtub Buoyancy results show several ways to propel toy boats.

It is always fun to build bathtub-sized boats. This video shows two handmade boats powered by battery packs and small electric motors that my son invented recently. A modified toy car powers the paddle boat; the air boat fan is a modified toy airplane propeller.

Why don’t you try inventing a boat?

For more ideas, try

A Simple Steam Boat at Curious Cat

Miniature Boats at HowStuffWorks

Hope you have fun and let us know what kind of boat you invent!

Edit: To check the rest of the posts on beach science, follow these links:

Sea Horses and Other Fish

Shore Birds

Tide Pool Invertebrates

Beach Science Algae

Beach Science-Sand

Beach Science-Seawater

What do you think? Are you ready to grow a giant pumpkin and give it a try?

Have a fun Friday!

Edit: Check this post for Why Pumpkins Float

1.    Wind or air movement
Probably the most obvious way to propel a boat without touching it is to use air movement or wind. We tried both creating a sail and blowing on it and also using a fan to create air. Both were effective, although somewhat slow and hard to steer.

2.    The classic balloon boat –

You may have seen instructions for these or tried out a kit. I found some available for sale on the Internet (see Resources below) or you can make your own. Check these fun instructions to build a balloon boat from ZOOM, the PBS TV show.

Note:  Please be careful using balloons, and always have adult supervision. Children under 8 years can choke or suffocate on uninflated or broken balloons.

3.    Wind-up propeller
My son took a wind-up propeller from a balsa wood airplane and modified it to propel a flat wooden boat. The stretched rubber band creates the potential energy which is then transferred to kinetic energy. It is fast for short distances.

See the red propeller on the right, rubber band across the center and nail holding it on the left.

4.    Magnet Repulsion
Okay this one was my idea. I remembered moving train cars in a wooden train set by reversing the magnets. It works with an egg carton boat, too. I think this type of boat has the best steering once you get the hang of it.

Here is a short video showing one of our trials. Bear with us, we’re still learning video technology

5.    Detergent Power / Soap propulsion

You may have seen instructions for a soap boat that actually moves. We created one using a top of a Styrofoam egg carton and a squirt of dish detergent. This is not technically a chemical reaction, the movement has to do with the surface tension of the water.

Instructions for a soap-propelled boat from CSIRO.

We simplified the technique a bit by just adding the dish detergent to an egg carton boat and it still seemed to work.

6.    Chemical reactions

My dad told me that as a kid he had a boat that ran on Alka Seltzer tablets. You can also make boats propelled by baking soda and water, or vinegar.

ZOOM has instructions for a Soda Bottle Boat

Good luck and I hope you try some of these. They were fun and we learned a lot too.

Resources for Further Explorations:

Balloon Powered Wooden Boat

Rubber Band Paddle Boat

Let’s Try It Out in the Water : Hands-On Early-Learning Science Activities (Paperback)
by Seymour Simon, Nicole Fauteux , Doug Cushman (Illustrator)

Teaching Chemistry with TOYS (Paperback) by Jerry Sarquis, Mickey Sarquis , and John Williams

Science in Seconds with Toys: Over 100 Experiments You Can Do in Ten Minutes or Less by Jean Potter

Magnetic Boats in the Tub