Just because school is out doesn’t mean that learning needs to end. But, since it’s summer vacation time, learning should be strictly fun in our book! We rounded up the coolest science experiments for kids that can be done on while enjoying sun, sand and surf. From the science of sand castles to studying the tides, here are a bunch of ideas to make your next beach day one to remember.

Before You Go

Look over the experiments below and pack along the needed items. Some will require assembly ahead of time, and most are easy to pull off, but if you’re like us, you might want to try them out by yourself before showing your kids in order to keep the eye-rolling to a minimum.

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The Science of Sand Castles

Things to Pack:
Sandcastle tools (pails, shovels, cups of different sizes, etc.)

Things to Do:
Scoop up the driest sand you can find on the beach and have your kid pack it in a cup as tight as they can. Turn it upside down and see what happens. When the sand comes pouring out, have your kid try it again with sand that has a bit more moisture and repeat. Continue doing so (perhaps adding a little water to the mix) until you get a nice solid cylinder of sand.

Things to Discuss:
Kids will clue in pretty quickly that wet sand holds together better than dry sand, but help them understand that water actually creates a thin “bridge” or “glue” that helps to hold the sand together. This is due to the surface tension of the water. Too much water and the “bridge” or “glue” gets broken down. Continue making observations throughout your masterpiece making. Make a moat. Does the water stay in place or does it get absorbed in the sand?

Filtering Water

Things to Pack:
Two empty bottles or canning jars
A funnel
A few paper towels
A few paper coffee filters

Things to Do:
In one bottle, place the funnel at the top and line with a paper towel. Fill the second bottle with dirty water (We suggest filling water from the lake or ocean and adding in sand granules, specks of seaweed, a teaspoon or two of dirt, etc. However, you don’t want really muddy water.). Pour the dirty water into the other bottle through the funnel. Next, replace the paper towel with a coffee filter and repeat the process. Then, do the experiment one more time with two coffee filters.

Things to Discuss:
At each stage, ask your kiddos what they see. Did the paper towel capture some of the dirt particles while others ran through? Does the water get cleaner the more filters that are used? Explain that we use filters all the time at home, and a water filter keeps the dirt out and makes the water safe to drink.

The Big Rocks in Life

Things to Pack:
Two large wide-mouthed jars
One smaller jar

Things to Do:
Collect two piles of large rocks or driftwood of about the same size. Then gather two piles of smaller rocks and shells, two piles of sand and a jar of water. Have your kid fill one jar with the sand, then the smaller rocks, and finally the larger rocks. There shouldn't be room to hold all of the big rocks. Then repeat the process with the other jar placing the big rocks in first, then the smaller rocks and then the sand and everything should fit. For the grand finale, pour the water into the jar.

Things to Discuss:
Were your kids surprised you could fit everything in the jar if they did it in reverse order? Did they think there would be a difference? This is an exercise that is often meant to symbolize life’s priorities, but it can also serve as a way to show spatial awareness too.

Become a Sand Inspector

Things to Pack:
A few sheets of black  and white construction paper
A magnifying glass
A magnet
A clear “zippable” plastic bag
A few toothpicks

Things to Do:
Place the magnet in the plastic bag. While holding the magnet, push the bag into the sand. Slowly lift the bag up. If your beach contains sand made from granite, then little black specks should be attracted to the magnet. Sprinkle these granules on the white paper. Then, sprinkle some lighter sand particles on the black paper and look at them through the magnifying glass. Try to pile the grains of different sand with the toothpicks.

Things to Discuss:
At first, all sand looks alike, but by looking more closely, you’ll see different colors and textures meaning that each sand particle came from much larger rocks of different colors and textures. The black sand is made of magnetite which forms when iron is mixed with oxygen.

Wave Watching

Things to Pack:
A watch or stopwatch
A pencil
Notepaper

Things to Do:
Look for an item bobbing up and down in the water like a bird or throw in a small piece of driftwood. Use your watch to time how long it takes for the object to go from the top of the crest to the bottom and back up again. That’s one bob. Record how long it takes for ten bobs to happen and then divide that number by ten. That will give you an average time for each wave’s period.

Things to Discuss:
When the water is at its high point, it is called a crest. When it dips down to its lowest point, it is called a trough. The space between two crests is called a wavelength.

Explore a Tide Pool

Things to Pack:
Water shoes – careful where you step!

Things to Do:
Look for periwinkles – little snails that live on the top of rocks in the “splash zone.”
Look for barnacles – grayish/white bits that look like tiny volcanos.
Look for mussels – blueish/black shellfish.
Look for sea anemones – they look like flowers.
Look for starfish

Things to Discuss:
All of these creatures are alive and are animals. When the rocks are dry, periwinkles will seal themselves up, so they don’t dry out. Barnacles close up when out of the water, but they feed on smaller plants and animals while submerged in the water. Mussels attach themselves to rocks so that they aren’t pulled away with the waves. Sea anemones will close up when gently poked. They stretch out in the water and shrink down when they are dry. Starfish “play dead” when they are out of the water but will slowly move when in it.

Make a Magni-Bucket

Things to Pack:
Plastic ice cream bucket or something similar
Plastic wrap
Large rubber band

Things to Do:
Before you leave the house, cut a hole (large enough to fit your kid’s hand in) about an inch away from the bottom of the bucket. When at the beach, cover the top of the bucket with plastic wrap and secure with rubber band. Make sure that the plastic wrap has some give to it. Pour water on top of the plastic wrap so that it sags down a bit. Then, have your kid hold different objects in the hole and look at them from the top of the bucket.

Things to Discuss:
The water is deeper in the middle and shallower on the sides just like a swimming pool and also like a magnifying lens making those objects appear larger.

Become a (Wind) Speed Racer

Things to Pack:
Two strips of cardboard
Four paper cups
Straight pin or thumb tack
Pencil with an eraser
Stopwatch
Pen and paper

Things to Do:
You’ll want to do the first part of this experiment at home. Cut out two strips of cardboard so that they are about an inch wide and about 12 inches long. Staple a paper cup at each end of the strips—one going the opposite direction from the other. Mark one cup with a large “X.” When at the beach, cross the cardboard strips together so that the top of each cup is pointed at the bottom of the next cup all the way around. Use the straight pin or thumbtack to puncture a hole in the middle of the strips and then stick it into the pencil. Facing the wind, see how many times the marked cup spins in 15 seconds. Multiply this number by four to get the total number of spins per minute, and mark down your findings. Repeat the process a few times during your beach visit.

Things to Discuss:
You created an anemometer. How did the wind speeds vary from each time you recorded? Was it faster in the morning or faster in the evening? When the wind pushed the cups, the air molecules caused them to spin around the pin. The faster wind pushed harder than the slower wind.

Whirlpool in a Bottle

Things to Pack:
Two empty and clear 2-liter bottles
Metal washer
Duct tape

Things to Do:
Fill one bottle with about two-thirds of sea or lake water. You might want to toss in a few specs of seaweed or leaves too. Place the washer on the bottle and line up the empty bottle on top of the water-filled one. Wrap the duct tape around the middle securing the two bottles together. Then, turn the bottles upside down.

Things to Discuss:
Does the water go straight down or do you see a mini whirlpool (Swirl the top bottom a bit for a better effect.)? The spinning water is called a vortex, and all tornadoes, hurricanes and typhoons are examples of air vortexes. Since you’re using water, this is an example of a whirlpool. As the water spins faster, it pushes to the outside of the bottle creating a hole in the middle. The air from the bottom of the bottle comes up the middle and the water from the top flows back down through the hole.

Hunting for Crabs

Things to pack:
Small shovels

Things to Do:
Walk down the beach toward the water, and look down for little holes. Sometimes you’ll find a bubble or two coming up. With your shovel, dig in the sand a few inches under the hole and scoop up the sand. When you brush away the wet sand, you might find a small crab or other creature.

Things to Discuss:
Crabs protect themselves by burying themselves in the sand when waves or other threats come by. While your kids might be tempted to take the baby crabs home to live as a pet, you’ll want to discourage this idea as they won't stay alive for long. 

— Jeffrey Totey

 

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