There's only so much pool and movie time before the brains start to atrophy, right? How about taking some of the kids' outside time and make it more constructive? Here are a few summer science experiments for kids to do this summer (suitable for 3rd-5th graders) that can pass the hours and have them learn something at the same time.

Cell Phone Experiment

Students in Sweden did this experiment to rave reviews and accolades earlier this year. They wanted to see how detrimental Wi-Fi cell phone signal radiation and waves were to living organisms. We're always trying to keep kids off their phones, right? What if they duplicated an experiment that demonstrates what might be detrimental to their very health? Read all about about this experiment at Mother Nature Network.

You'll need cell phones and plants of the same species that are also the same age. This experiment could take them to the end of the summer and might just scare them into not having cell phones glued to their ears.

Particle Experiment

This one has been around a long time, but is a great one to demonstrate to kids what it is we're breathing and why keeping air as clean as possible is important. Kids with asthma, of course, know the lessons of this one. It's the great paper plate experiment.

You'll need paper plates and tape. Take a series of paper plates and tape them to a surfaces outside of the house. Label them 'one day', 'two day', 'three day', etc. Put at least three plates in each location (one for each day). Coat each plate with double sided tape on the front.

After each day, have the kids look and see what's stuck on the tape and how many days it takes for it to be completely covered. Are there some areas of the yard that attract more air debris than others? Was there a forest fire? If they have friends or cousins in different areas of the country, have them do the same experiment and compare with the kids in other places.

Tide Experiment

A trip to a beach or a lake is a great opportunity for a science experiment. Why not learn about tides? If the kids are going to the same beaches everyday at various times they can record tides and tide changes. Supplement that with this little educational video from BodhaGuru Learning and you've got a great learning experience.

Sand Experiment

Instead of collecting expensive T-shirts at every beach stop, what if the kids collected a teaspoon of sand to examine the contents under a microscope once they get home? They can make labels and you can get small vials. Have them write descriptions and study the contents of each sand stop. Now they have a keepsake that they learned about, too!

Plastic Beach Experiment

It's not always easy to wean kids off of unnecessary plastic objects, or to not want a new bag or a new juicebox everywhere they go. It's important they know and understand where these things end up. Do they know about plastic beach yet? Check out this clip to get them rolling. 

For this experiment, have each kid measure off a square foot of beach. Next, give each one a sifter of some sort — a plastic colander from the thrift store works fine, or you can use screens from the hardware store. Have them excavate their square foot of beach and write down what they found. Then have them compare results. Ask them to think about where the debris came from. Are they on the West Coast and getting debris from Asia? Are they on the East Coast and getting debris from Africa?

Storm Experiment

Teachers everywhere lament how kids lose their math skills over the summer. Here is a science experiment that keeps those arithmetic skills fresh.

Are you in a region of the country that gets those summer thunderstorms? First explain thunder and lightning and why lightning always follows thunder. Here's a good, quick explanation. Lightning moves at the speed of, well, light. Sound however is much slower. Counting the seconds between a flash of lightning and the boom of thunder tells us how far away a storm is. When the kids see a flash of lighting, have them count slowly until they hear thunder. Then have them divide that number by 5. Their answer is distance in miles between them and the storm.

Sun Experiment

Why not have them practice telling time the old fashioned, non-digital way? Have them create a sun dial in the backyard. Tell them they have to come in when the shadow falls on a mark you designate.

What experiments will you conduct with your kids to keep those science brains running during the rest of the summer?