Monthly Archives: October 2013

Twisted Bones

We’re knuckle deep in a bone unit study right now.  Get it?  Knuckle deep!

Here’s an experiment we did over the past 24 hours, which amazed all of us:

Twisted Bones

2013-10-21 12.19.06For this experiment, you’ll need a baby food jar (or any size jar to fit your bone), a chicken or turkey bone (I was going to use a wishbone, but couldn’t find it.  I ended up using several smallish bones instead), baking soda, water, a bowl, rubber gloves, and 6% hydrochloric acid (I used 36% because that’s what Home Science Tools happens to have.  I diluted it with water).

Here’s what you do:

  1. First and foremost, know that hydrochloric acid is in fact…an acid.  Kids, let your parents handle this for you.  It’s corrosive and could be harmful if touched or swallowed. Parents, be sure to wear rubber gloves.
  2. Put your bone(s) in a jar along with the hydrochloric acid.
  3. Let it sit overnight.
  4. In the morning, put on rubber gloves, and transfer the bones into a bowl with a solution of 1 cup water, and 2 teaspoons baking soda.  Swish them around a bit to dilute and neutralize the hydrochloric acid.
  5. After a minute or two, take them out.  What do they feel like?

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Now, you can do something cool with the bones!  Are they long enough to tie into a knot?  Our weren’t so we twisted them together.

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Why does this happen?

The hydrochloric acid dissolves the mineral salts, leaving behind a bendy, cartilage remnant.

Soda Pop Science

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Whether you choose to drink pop in your home or not, there’s no denying the fun when it comes to experimenting with pop during science class!

We read the book Soda Pop Science Projects Experiments With Carbonated Soft Drinks  by Thomas R Rybolt, 2004(which appears to be out of print.  There are a few “used” copies on Amazon, or else you could check your local library), and were inspired to try a few of the experiments.  This book is great because it spans a wide range of ages.  My kindergartner enjoyed the experiments, as did the 2nd and 4th graders.  We didn’t even touch on the mathematical equations and chemistry that we would have if the kids were older.

Here are the FIVE experiments we chose to do from the book (plus one that wasn’t in the book, just for fun!):

Cola Float

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For this experiment, you’ll need a can of Coke and a can of Diet Coke, plus your kitchen sink filled with room temperature water.

Have the kids make a hypothesis as to whether or not the cans will sink or float.  Then, drop the cans into the water.  What happens?  Why do they think they got the results they did?

Make a note of how much sugar is in each can.  Do the kids think the sugar could play a part in whether the cans sink or float?

Here’s why it happened:

“When more sugar is added to a drink, the density is increased and the can is more likely to sink.” (Rybolt, 2004, p. 13)

Changing the Density of Water

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For this experiment, you’ll need several small water bottles (we used 5), and several teaspoons of sugar (we used 26), and your kitchen sink filled with water.

Mark the tops of your water bottles with the numbers 0, 2, 4, 6, and 10 (you can change this up if you want.  You’ll just want a wide spread).  Now, have the kids funnel the teaspoons of sugar as marked on the tops of the bottles.

Have them make a hypothesis about what they think will happen when the different sugar bottles are dropped into the water.  Then, drop them in!

What happened?  The sugar makes the water more dense, therefore the water bottles with the most sugar in them, will sink to the bottom.

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Trapping Carbon Dioxide

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For this experiment, you’ll need a can of Coke and a can of Diet Coke, two one gallon Ziplock bags, and a sink.

Have the kids place a can of pop into each gallon Ziplock.  Squeeze all the air out of the bag.  Have them make a hypothesis about what they think will happen when you open the can up and dump the contents into the bag, while it’s sealed.  Will the Diet Coke have more carbon dioxide, or regular Coke?

Now, carefully open the cans of pop and pour them into the bag (all while the bag is sealed).  Let them sit for an hour to see how much carbon dioxide escapes into the bag.

What happened here?  ”In a closed soda bottle, water molecules surround molecules of carbon dioxide.  When you open a soft drink bottle, carbon dioxide gas that is dissolved into the water of the cola bubbles out of the liquid.  As the carbon dioxide gas leaves the liquid, it fills the empty bag” (Rybolt, 2004, p. 32).

Removing Color

For this experiment, you’ll need about a cup of activated carbon (available on Amazon or at a pet store in the fish tank area), four empty 16 oz water bottles, a funnel, ruler, Diet Coke, and grape pop.

First, pour about five inches of grape pop into an empty bottle, and five inches of Diet Coke into another empty bottle.  These are going to be your “control” bottles (the bottles that you’ll compare your color changes to).  Next, funnel about 3 inches of carbon into the bottom of the remaining two bottles.  Fill those bottles up with water, let them fit for a few minutes, and pour out the water (be sure not to let the carbon pieces fall into your sink drain).  Now, pour Diet Coke in one of the carbon bottles so that it reaches five inches, and do the same for the Diet Coke.

Have the kids make a hypothesis about what will happen to the grape pop and Diet Coke over the next 12 days.  Make and record observations over the next four days, to see what happens to the color of the pop.

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This is so cool! The one one the far right was grape pop one day ago. Now it’s completely clear!

 

What’s happening? “Molecules such as those responsible for color can be removed from water because they stick on the surface of carbon particles.  This process is called adsorption and can be used to purify water” (Rybolt, 2004, p. 54).

A Tasty Smell

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For this experiment, you’ll need a bottle of Sprite for every child participating, plus a few other “smelly” soft drinks such as root beer, grape pop, orange pop, etc, and straws.

The goal of this experiment is to see if smelling a specific flavor of soda can change the way we taste another kind of soda.  Have your kids make a hypothesis about what will happen when they drink Sprite, while smelling a different kind of soda.

To do this experiment, put a blind fold on the child doing the experiment.  Have him/her take a sip of Sprite, while smelling another kind of soda.  Try it with the other flavors of soda.

Did the child taste what he/she was smelling?  Or did he/she taste the Sprite?

And last but not least, since we were up to our eyeballs in soda, we decided to do the old Mentos in a bottle of pop experiment.  You know, the one where you drop the Mentos into a 2 Ltr bottle of pop, and it fizzes up into a towering inferno of stickiness?  Tip:  If you use diet pop, it doesn’t leave a sticky mess!

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