Apple Float or Sink?

Fall is a fun time to play with apples and go apple picking.   If you have a few extra apples laying around, here’s a great investigation for the tiny tots in your home to investigate whether apples sink or float when placed in water.

Here’s what you need to get started:

  • apples of different varieties (we used, Fuji, Granny Smith and Red Delicious)
  • Bin with water
  • Knife (to cut apples, for adult use only)

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Have your superheroes hold the apples in their hands and predict what will happen when it is placed in water.  We tried 3 different types of apples, making a hypothesis (prediction) before placing each one in the water.

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First the Granny Smith apple

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Then the Red Delicious and Fuji apples

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All three apples floated.  There was no difference between the 3 varieties.  But why did they float?  Apples have a lot of small air pockets inside that cause them to float in water.

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But what about the individual apple parts?  Do all the apple parts float? We decided to find out by cutting an apple open and testing each part in a cup of water.

What we noticed was the apple pieces and the peel still floated in water.

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But, the stem and the seeds did not float.

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This was a great investigation on floating and sinking using apples!  And while you have a bunch of apple parts lying around, try exploring your 5 senses using apples.  Or let the little ones “bob” for apples!

For more Apple Science Activities, try:

The Science behind the Activity:

Apples contain quite a bit of air inside them which causes the overall density of the apple to be less than that of water, so it floats.  By testing the individual parts, we can see that not all parts of the apple float in water but when all the parts are put together they do.

 

Fireworks in a Jar

New Year’s Eve  is coming up and here’s an easy colorful way to get your holiday started with some science!  Just 3 ingredients from your pantry.

Here’s what you’ll need to get started:

  • water
  • oil (we used vegetable oil)
  • food coloring
  • clear empty glass jar (we needed two because each of my older boys had to have their own)
  • clear small glass bowl
  • fork

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First we filled the empty jar with water. We filled 2 jars because my older sons MUST have their own jars.

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In the small bowl, we added about 1/3 cup of vegetable oil.  The actual amount doesn’t really matter.

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Add a few drops of food coloring to the oil.  We added a few drops of each color.

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Notice that the food coloring doesn’t mix or dissolve but remains in droplets in the oil.  Use a fork to mix the droplets with the oil.  The color will not dissolve but the droplets will break into smaller droplets which is what you want.

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Now the fun part!  Pour the oil into the jar with water.

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The oil will float at the top because oil and water do not mix and oil is less dense than water.

Be patient.  In less than a minute, you should see the colors drip from the oil and into the water, looking like fireworks in the water.

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The different colors will mix and form new ones.  It really is so fascinating to watch!

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Even our littlest superhero came over to see what the fuss was all about.  He promptly shook the jar as toddlers usually do 🙂  Good thing I took pictures before he got to experimenting!

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The Science behind the Activity:

Oil and water are known to be immiscible, meaning they do not mix or dissolve into each other.  Chemically this is because water is polar and oil is nonpolar.  Food coloring dissolves readily in water but does not dissolve in oil.  When the oil is poured into the water, the oil will float on top of the water for 2 reasons: 1. because water and oil don’t mix and 2. because oil is less dense than water.  As the drops of food coloring fall to the bottom of the oil layer, they meet the water and immediately mix and dissolve, creating the pretty swirls.

For more details and to see where I got this idea from visit this link:  http://www.exploratorium.edu/blogs/spectrum/fireworks-bottle

 

 

Ocean Zones in a Jar

If you’ve ever tried the liquid layers in a jar, here is a great twist for showing your superheroes the layers in the ocean.  This activity definitely requires some help from an adult to do but my preschoolers really enjoyed watching the layers stack on top of each other.  Older kids will love doing it on their own. ( I also have Simplified Ocean Zones in a Bottle for the youngest superheroes as the layers in this one can get tricky at the end.)

Here’s what you’ll need to get started:

  • Light Karo syrup (corn syrup) – tinted black or dark purple OR Dark Karo Syrup (no tinting needed)
  • Blue dish soap
  • Water tinted light blue
  • Vegetable oil – tinted blue-green (if possible)
  • Rubbing alcohol (91% works best)
  • Dropper
  • Funnel
  • food color (or liquid watercolors)
  • glass jar (I used a pint sized glass jar)

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First add about 1-1.5 inches of corn syrup to the jar.  Add some black/dark purple color to it and mix well.  (For my Tiny Tot class, I tried the dark Karo syrup and it worked great since we didn’t have to tint it black) This represents the deepest ocean zone, the Trench.

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Carefully add the blue dish soap on top of the corn syrup layer.  The layers should not mix.  This second layer represents the Abyss.

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Next carefully add the blue water.  Don’t tint it too dark.  The water layer should sit right on top of the dish soap creating 3 distinct layers. The water layer represents the Midnight Zone of the Ocean.

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The next layer will be the oil.  Food color and watercolor will not dissolve in oil since they are water based and oil and water don’t mix.

Regular food color will NOT mix with oil

Regular food color will NOT mix with oil

For this layer, you have 2 options: leave it yellow OR if you have candy food color (oil-based food color) then you can use that to tint the oil.

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Either way, you will definitely get a distinct layer on top of the water.  I used the candy color to get a greenish-bluish color.

Oil-based candy color WILL mix with oil

Oil-based candy color WILL mix with oil

This layer represents the Twilight Zone.

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The last layer is a bit tricky.  The rubbing alcohol to use should be 91%.  The 50% definitely didn’t work and the 70% was not too successful either.  We poured some rubbing alcohol into a cup first.

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Use a dropper to slowly add the rubbing alcohol  by touching the edge of the jar so that it drips down the side.  Be careful not to let it break through the oil layer or else it will mix with the water.  It will be slow-going but will slowly reveal a clear layer on top of the oil layer.  This layer represents the Sunlight Zone, the part of the ocean where most marine life exist.

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All done!  You can also add labels to the outside of the jar to show your superheroes the layers.

Visually you can see how the layers (ocean zones) get darker as you go deeper.  From the picture it is hard to tell that the layers are getting darker at the top (the oil looks darker than it actually is). You can discuss with your little ones what effect this might have on the marine life that lives in each layer.

The Science behind the Activity:

There’s all sorts of awesome science in this activity!  This is a great visual representation of how the layers of the ocean have varying amounts of light reaching them.  This can open up an entire discussion of why there are so many more organisms in the Sunlight Zone and the Twilight Zone versus the Abyss and the Trench.  You can even research what types of organisms exist in each layer.

The other awesome science in this activity has to do with the different densities of various liquids.  Liquids that are more dense (more mass per volume) will sink and liquids will lower densities will float on top of denser ones.  If you have ever tried to mix oil and water, well, you know why that won’t work because oil is less dense than water.  This is why you have to shake your favorite salad dressings before pouring.

Here’s where I got my idea from: http://www.icanteachmychild.com/make-ocean-zones-jar/

Extension: This activity goes really well with my Exploring Life in the Ocean Zones activity.

Ocean in a Bottle

For my ocean themed class, I thought it would be fun to make an ocean discovery bottle.  If your kids love to collect shells and rocks and the beach (like mine do), this is a perfect extension activity for when you get home.  This is an easy activity for the kiddos to do and there are so many fun ways to play and learn with them.  And there are so many variations you can add to yours.

Here’s what you’ll need to get started:

  • Empty water bottle with a cap
  • Funnel
  • Water tinted light blue
  • Sand (we used play sand since that’s what I had at home)
  • Sea shells that are small enough to fit inside a water bottle (I picked up a pack at Michael’s but you could use some that you’ve collected at the beach yourself)
  • Little fish/sea creature figurines (I couldn’t find any that were small enough to fit through the mouth of our bottle)
  • Foam ocean stickers/shapes (we peeled the backing off the stickers since I couldn’t find just the foam shapes)IMG_1675

First we added about 2 inches of sand to an empty water bottle.  We used a funnel to make it easier.

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Then they added the sea shells.

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Next we added the foam shapes after peeling the paper backings off them.  We didn’t want to “pollute” our ocean:)

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Using a funnel, the boys added the blue ocean water to the bottle.  Screw the cap on.  (You can also use a hot glue gun to attach the cap so it can’t be opened)

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And THEN the fun began.  Almost immediately, my middle son started shaking his bottle.

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My oldest son decided to roll his bottle and make waves.  They tried to find their sea animals and sea shells.

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That’s it!  So easy!  And lots of shaking going on over here!

The Science behind the Activity:

Discovery bottles are great for toddlers and preschoolers as it gives them a chance to explore cause and effect.  “If I shake this bottle, what will happen?”  For preschoolers and a bit older, you can discuss the motion of water and waves.  A variation to this is to make it with oil and water instead of sand and water and you can discuss concepts such as density and why water and oil don’t mix.  Endless options!  What variations have you tried?

 

 

What Floats Your Boat?

What kid doesn’t like to play with water?  Add a bit of science and math to your water play next time with this easy experiment to set up at home.  I used to to this same experiment with my middle schoolers in the classroom to demonstrate concepts in buoyancy but for the little ones, it is just fun!

Here’s what you need to get started:

  • small bin or deep dish for water or even your water table!
  • water (I added some blue color for fun)
  • Foil
  • pennies or small rocks

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Add some water to the bin.  My kids love colored water so we added a drop to simulate ocean water.

The tricky part is making the foil boat.  Younger kids might have trouble with this and might tear their boats.  Feel free to help them. Ours looked like bowls.

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Place the foil boat in the water and make sure it floats and doesn’t have any leaks.

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Next, we added pennies, one by one, to the boat.

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You will be amazed at how many pennies this little foil boat can hold!

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And then there was one penny to many… and the boat finally sank!

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Lastly, they colored in their lab sheet and had to write the number of pennies their boat held before sinking.  There you go!  Math, science, coloring and some healthy sibling competition:)

Extensions for older kids: Compare what happens to 2 identical pieces of foil when placed in water: one in the shape of a boat and one wadded up super tight to minimize the amount of air trapped inside.  Why do you think this is possible?  Also, try this experiment with salt water.  Predict what effect salt water would have on the boat’s ability to carry cargo.

The Science behind the Activity:

When doing this experiment with older kids, I discuss the concept of buoyancy, which is the ability of an object to float when placed in a fluid.  Surface area greatly affects the buoyancy of an object.  The larger surface area allows the force (weight of the cargo/pennies) to be spread out over a larger area, thus allowing the boat to float even with the “cargo”. The larger surface area displaces more water.  This is why a large hull in a ship is able to float on water.  And if the ship is floating on salt water (like the ocean) it can carry even more cargo since salt water is denser than pure water.  It’s a bit more complicated than my simplified explanation, but hopefully you get the point.  And for the little ones, it’s just fun to sink the boats:)

For a more detailed explanation click on this link:

http://www.coolscience.org/CoolScience/Teachers/Activities/FoilBoats.htm

Homemade Lava Lamps

I loved those fancy lava lamps when I was a kid, but alas, my parents did not buy one for me.  Here’s a DIY Homemade Lava Lamp with some science sneaked in!  Super easy and mesmerizing for the superheroes in your life!

Here’s what you need to get started:

  • Empty water bottle (or any clear bottle)
  • vegetable oil (any light colored oil will do but this is probably the cheapest)
  • Food coloring
  • alka seltzer tablets

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Fill the bottle a little more than halfway with oil.

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Then add water to it until it’s about an inch or two from the top of the bottle.

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Add about 5-10 drops of food coloring. Watch how the color drips down through the oil to the water.

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Break one of the alka seltzer tablets into 4-5 pieces.  Use caution with young children who might be tempted to put this in their mouths!  It is a cold medication and should not be ingested by children!  IMG_1984

Add one piece to the bottle and watch the magic begin!

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Once the alka seltzer tablet has completely dissolved, add another one and watch the colored bubbles rise and sink again!  Repeat as many times as you’d like!  You can even try adding some glitter for some extra fun!

The Science behind the Activity:

Water and oil are insoluble, they do not mix.  Water is denser than oil and stays as a separate layer at the bottom of the bottle.  Food coloring is soluble in water so it colors the water but not the oil.  When the alka seltzer is added, it forms gas bubbles that rise to the top, “dragging” the colored water along with it.  As the water reaches the top and the gas bubbles pop near the surface of the oil, the denser water falls back down through the oil.  The process keeps repeating itself until the alka seltzer has completely dissolved an no longer forms any bubbles.

This activity can be done with adding salt instead of alka seltzer (for those of you who are concerned about using medication with kids) but the results are not as good and eventually the salt saturates the water and makes it cloudy.  Let me know if you try it with some other fizzy tablets such as Airborne.  Curious to see if those work just as well.

Follow this link to see where I got the idea from and more details about the experiment: http://slsmithphotography.typepad.com/my_weblog/2010/06/lava-lamps-summer-fun.html

Soap Souffle

We are about one week away from school starting and it is getting harder to keep the superheroes entertained.  While the baby was napping, we decided to do a quick experiment.  Little did I know that this was going to keep them busy for over an hour!  So grab a bar of Ivory Soap and have some “clean” fun!

Here’s what you’ll need to get started:

  • Ivory Soap (No other brand will do)
  • Paper Towel
  • Microwave
  • Empty bin (optional)

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Unwrap a bar of Ivory Soap and have your superheroes observe it.  If they are younger, ask them probing questions:

  • What shape is it?
  • Is it soft or hard?
  • What color is it?
  • Is it smooth or bumpy?
  • Does it have a smell?

We cut the bar of soap in half.  Place it on a paper towel (we used two sheets) and place in the microwave on high for 1-2 minutes. (Ours was done in about a minute)

Have your superheroes WATCH through the microwave (mine had to stand on chairs to see).  They will be amazed at what they see!

Take your soap out of the microwave.  It will be warm so touch it first before allowing your little ones to touch it.

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Ask them to describe what happened and how it has changed.  Then I put it in a bin and let them play with it.  So much fun!  They called it “snow”.

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And when they were done, they only needed to wash their hands with water and that got me thinking… what if we add water to the crumbled soap?  And so we did.  The superheroes predicted it would make bubbles since that is what happens when we add soap to the water during bath time.

And now we had even MORE fun.

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And clean-up is easy!  Their hands are already soapy so a quick rinse is all they need.  Please note that I would play with the crumbly soap outside as the dust particles caused my little ones to sneeze a bit indoors 🙂

Observation Sheets

Observation Sheets

Extension:

For older kids, you can test this with another brand of soap and see what happens.  Prior to placing the soap in the microwave, have them place each bar in a bowl of water to see if there is a difference in how they behave in water (this is the reason why only Ivory soap works) and what that might have to do with the end results.

The Science behind the Activity:

Ivory Soap is one of the few brands of soap that has air whipped into it during the manufacturing process so it is less dense than water, therefore it floats in water.  Because of this air trapped inside when the soap is heated, the trapped air molecules move faster forcing the soap to expand.  The heat also makes the soap a bit more pliable, thus adding to fluffiness.

To see where I got the idea from and a fabulous, detailed explanation, follow the link below:

http://www.stevespanglerscience.com/lab/experiments/soap-souffle

 

Dancing Raisins

Today we were supposed to go to the park but the littlest superhero refused to nap and when he finally did, it was too hot to go outside.  So, we looked in the pantry and had a “dance party” with raisins and soda!

Here’s what you’ll need to get started:

  • Raisins (Leftover from the goodie bag from a week ago)
  • Soda water, Ginger ale, sprite, club soda, sparkling water or whatever clear bubbly (kid-friendly!) you have at home
  • clear jars or cups

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We used some leftover Sparkling water and a Diet Ginger Ale, but any clear bubbly soda should work fine.  We added them to the empty jars.  I then asked the superheroes what they think would happen when we added the raisins.  My older one has taken to snooping over my shoulder when I’m on Pinterest so he already knew the punchline.  Darn!  But my middle one was MESMERIZED by the raisins bouncing around and all those fizzy bubbles!

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It really looked so cool watching the raisins float up and then sink down.  The raisins in the Ginger Ale were more active than the ones in the Sparkling Water.  I assume this is because we used a bottle of sparkling water that had been opened previously and the Ginger Ale was a new can.

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We will definitely be trying this again with several other sodas as well as with a fresh bottle of sparkling water!  You can also make a bubbly solution with vinegar and baking soda as well. (We used up all our baking soda playing with vinegar a few days ago so we will have to try that next time as well)

Another extension/variation of this experiment is to try out different items, other than raisins that might behave in a similar way, such as dried cranberries, dried macaroni, popcorn kernels, etc…  Search your pantry.  The options are endless.  Happy Dancing!

The Science behind the Activity:

This is a great experiment demonstrating sinking and floating.  Raisins are denser than the liquid so they initially sink when you put them in.  As the carbon dioxide gas bubbles attach to the surface of the raisins, they decrease the density of the raisin and the raisin floats to the top (dances and shimmies its way to the top!) At the surface of the liquid, the gas bubbles pop and the raisin sinks back down.  The process keeps repeating until there isn’t enough carbon dioxide left to raise the raisins (pun intended!).

To see where I got the idea from and more details, follow the link below:

http://www.stevespanglerscience.com/lab/experiments/dancing-raisins-the-bubble-lifter