Apple Volcano

This was our first full week of fall and it’s been HOT and sweltering over here.  Finally today, it feels like Fall and it’s a perfect day to celebrate apple season.  Aside from eating and baking apples, why not use some over-ripe apples to play with? Here’s an easy twist on the classic “volcano” experiment, just in time for Apple season.  So, while you are picking out your apples, get a few extra and let your little ones have some explosive fun!

Here’s what you need to get started:

  • Apples (any variety will do)
  • Baking soda
  • Vinegar
  • Food coloring/liquid water colors (optional – but everything is so much more fun with colors!)
  • Knife and metal spoon to hollow it out (Adult use only)
  • droppers and spoons
  • cups
  • Tray to contain the mess

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First cut the top off the apple and scoop out the insides and the seeds to form a “bowl”.  I found it easiest to cut a circle off the top and then use a metal tablespoon to scoop it out.

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This kept the top of the apple intact to use as a lid.  We saved the seeds and stem for our Exploring the Five Senses with Apples activity.

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I set up a tray with the hollowed apple, dropper, cup of baking soda, spoon and cup of vinegar (I colored ours red for fun)

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Then I invited the superheroes to play.  These little ones KNOW exactly what to do with baking soda and vinegar!

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Repeat as many times as your superheroes want to do it.  We went through a box of baking soda between the two older ones!

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The Science behind the activity:

This is a classic acid-base reaction.  Baking soda is a base and vinegar is an acid.  When they combine, they create a chemical reaction where the baking soda neutralizes the vinegar.  A by-product of the reaction is carbon dioxide.  That is what the bubbles are.  As the carbon dioxide is formed and bubbles out, it carries some liquid up with it, hence the “eruption”.

Extension: 

There are a million ways to do this experiment.  I can pretty much adapt this to any theme.  Another great Halloween theme application of this is the Pumpkin Volcano, which we also did.

For my Tiny Tot class, I ended the class by reading “Ten Apples On Top” by Dr. Seuss.

For more Apple Science Activities, try the following:

 

 

Purple Potion Reactions (Cabbage Juice Indicator)

I’ve been wanting to do this simple kitchen science experiment with my kids for awhile now as I used to do this with my middle school students once upon a long time ago…This one is fantastic for superheroes of ALL ages.   The younger ones can enjoy the colorful reactions and the older ones can learn a bit about acids and bases and how pH indicators work.

Here’s what you need to get started:

  • Red Cabbage (Why is it called red when it really looks purple??)
  • Large Pot
  • Strainer
  • Ice Cube Tray (or several small clear cups/jars)
  • Droppers (I save the ones we get from the pharmacist everytime one of my superheroes needs meds)
  • Coffee Filters (optional)
  • Household liquids to test (water, vinegar, lemon juice, fruit juice, milk, baking soda/water, soda, laundry detergent, liquid soap, ammonia, etc…)

To make the Purple Potion:

Coarsely chop up half a head of cabbage.

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Place it into a large pot and add water.  I added about 5 cups of water to mine.

Bring the cabbage/water mixture to a boil and then let simmer for about 15-20 minutes.  Make sure you have your exhaust fan on and your windows open.  This gets stinky 🙂

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Remove from heat and let cool to room temperature so that it doesn’t burn your little ones.  Once cool, strain the mixture so that only the purple liquid is left.  Discard the cabbage.

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I ended up with about 4 cups of Purple Potion.  Now we are ready to experiment!

IMG_1476To Experiment:

I placed an ice cube tray in front of each of the Superheroes.  I placed a variety of liquids from the kitchen into several wells of the tray.  We used: water, milk, lemon juice, liquid soap, baking soda (dissolved in water), vinegar, apple juice, liquid soap and laundry detergent.

I had them color in what the liquids looked like before we started.

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This is the observation sheet they used:

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Each superhero got a small cup of Purple Potion in a cup and a dropper.

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They added several drops of the purple potion to each well and observed the changes.

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Whoa!  Look at all those colors!  Why is it doing that?

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Here are the final results:

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I asked them what might happen if they start mixing some of the liquids together.  A whole new set of experiments to do!

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My older son made a pink concoction and said it looked like “antibiotics”! (Can you tell how sick we’ve been this past winter! )

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With my older son, I probed him on what the pink colored liquids had in common and what the blue colored liquids had in common.  I think this was a bit over the top for a 6 yr old and he really was a bit lost at what to say.  If you have older kids, definitely ask.  The goal is to see if they can come up with some common characteristics of acids and bases. (Even my middle school students used to struggle with this)

Extension:

I decided to try to make my own indicator paper with some of the Purple Potion.  I placed 4 coffee filters in a container and added some Purple Potion to it.

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I soaked the filters overnight. Make sure to use an airtight container with a lid or your kitchen will stink in the morning!

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Remove the paper from the liquid and let dry completely.  I left mine outside to dry in the sun.

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Cut into strips and you’re all set!

Instead of using droppers to test the liquids, you can dip the indicator paper into the liquids and see the paper change colors.

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And then they placed it on their observation sheet to compare with their previous results

IMG_1509Science Behind the Activity:

Cabbage juice acts as a pH indicator.  Without getting too deep into the chemistry of it all, substances that are acidic (pH between 0-7) will turn varying shades of pink/red when mixed with cabbage juice,  Substances that are basic (pH between 7-14) will turn varying shades of green-ish/blue when mixed with cabbage juice. There are several types of indicators that are used for different purposes. Litmus paper is specially treated paper that turns red in the presence of an acid and blue in the presence of a base.  By treating the filter paper with cabbage juice, you can create a simple version of indicator paper.  There are also several different types of indicator paper as well, many that can give you an approximate pH of the substance being tested so that you can tell just how acidic or how basic the substance is.

 

Pumpkin Volcano

So who doesn’t love a little vinegar and baking soda action?  Here’s an easy twist on the classic “volcano” experiment, just in time for Halloween.  So, while you are picking out your pumpkins, grab a small sugar pumpkin and let your little ones have some explosive fun!

Here’s what you need to get started:

  • Small Pumpkin (I used sugar pumpkins that were 2/$1 at our local produce stand but you can also use the small decorative pumpkins too)
  • Baking soda
  • Vinegar
  • Food coloring/liquid water colors (optional – but everything is so much more fun with colors!)
  • Small cup (optional)
  • Syringes and droppers (optional-my kids love using these!)
  • Dish/Container to place the pumpkin in to catch the “eruption”

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First, cut the top of the pumpkin out and scoop out the seeds.

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Mini Decorative Pumpkin

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Sugar Pie Pumpkin

 

 

 

 

 

 

 

We tried the experiment by adding our “chemicals” directly into the pumpkins, but the baking soda started clumping up after awhile and it was hard to clean them out in between students.

So, we cut off the top of a small plastic cup so that it fits inside the pumpkin.  This is optional but we found that it was easier for repeating the experiment if there was a cup inside.  It is by no means necessary.

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Next, we poured some vinegar into a cup.  My superheroes chose to add red liquid watercolor to make “vampire’s blood”.  For my science class, I had 6 rainbow colors for the tots to choose from.

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Add a teaspoon of baking soda into the pumpkin

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Then add some vinegar (vampire’s blood!).  My superheroes love using droppers.

IMG_2338Watch your pumpkin-cano erupt!

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Repeat as many times as your superheroes want to do it.  We went through a box of baking soda between the two older ones!

In my Tiny Tot class, I gave each child a tray with cups of colored vinegar and baking soda for them to do some free play

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When I did this with my son’s Kindergarten class, we added some spiders and plastic eyeballs for some extra fun.

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The Science behind the activity:

This is a classic acid-base reaction.  Baking soda is a base and vinegar is an acid.  When they combine, they create a chemical reaction where the baking soda neutralizes the vinegar.  A by-product of the reaction is carbon dioxide.  That is what the bubbles are.  As the carbon dioxide is formed and bubbles out, it carries some liquid up with it, hence the “eruption”.

Extension: 

There are a million ways to do this experiment.  I can pretty much adapt this to any theme.  Another great fall theme application of this is the Apple-cano, which we also did.  This time the superheroes chose “green slime” as the color of the eruption.

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For other fun Pumpkin and Halloween related science activities, try:

 

Eggs-periment Part 2 – Investigating Naked Eggs

So now that we know how to make a NAKED egg (giggle, giggle) we can investigate osmosis which is the movement of water through a membrane.  It’s best if you have 4 naked eggs.  If you don’t know how to make a Naked Egg click here.

Here’s what you need to get started:

  • Naked Eggs (We used 4 and 1 broke)
  • Water
  • Food coloring
  • Salt
  • Corn Syrup
  • Clear Jars/Cups

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I helped the superheroes take the eggs out of the vinegar that the eggs had been soaking in (to dissolve the shells) and rinsed the outside with water.  Next, we gently placed them back in the clear jars.  Unfortunately, one broke (our salt water egg) so we were left with 3 naked eggs.  We poured water over one egg, water with green food coloring over the 2nd egg and corn syrup over the last egg.  And then we let them sit overnight.

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Left to Right: Water, Green water, Corn Syrup

Because the eggs had absorbed water from the vinegar solution, the egg in the corn syrup began to float (water is less dense than corn syrup so the egg floated a bit).  This will not affect your results.

After 2 days of soaking, the eggs looked like this (from the top):

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Left to right: Water, Green water, Corn syrup

You can see the water egg has turned white again and has gotten bigger.  The egg in the green water has turned green.  Interestingly, the egg in the corn syrup has begun to shrivel up and the yolk is very visible.  We took the eggs out of the jars to investigate them a bit more.

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Left to Right: Raw Egg w/Shell, naked egg in water, Green water naked egg, Corn Syrup Naked egg

I asked the superheroes what they think happened.  The green egg was the easiest for them to understand.  My little superheroes were pretty impressed with the shriveled egg.  I let them hold the eggs and feel the differences between the eggs.

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Egg in water

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Egg in green water

Egg in corn syrup

Egg in corn syrup

And of course, the superheroes completed their observation sheets.IMG_1913

 The Science behind the Experiment:

What is going on with the naked eggs?

Once the shell disappears, a permeable membrane remains.  Permeable means that substances can penetrate (or diffuse into) the membrane, such as water.  This process is called osmosis, the diffusion of water.  Water tends to move from areas of higher water content to lesser water content until the water content on each side of the membrane is equalized.

In the case of the eggs in water and green water, the water content inside the eggs was lower than that outside and so the water moved into the eggs and made them bigger.  The membrane to the egg is also permeable to food coloring so that is why the egg in green water turned green.

In the case of the egg in corn syrup, the water content of corn syrup is lower than that inside the egg so water moved out of the egg and into the corn syrup.  This caused the egg to shrivel up.  If our salt water egg had not broken, what do you think might have happened to the egg?  Test it out to see if your guess (hypothesis) is correct!

Many secondary teachers use this experiment to demonstrate how the membranes inside of our cells work.  Our cell membranes are semi-permeable which means some substance can penetrate the membrane and others cannot.  This characteristic is vital to how materials move in out of out cells and our bodies.

Follow this link for more details about this experiment:

http://www.exploratorium.edu/cooking/eggs/activity-naked.html

 

Eggs-periment Part 1 – Naked Eggs

The kitchen is the BEST place to look for materials to investigate with your kids.  This past week, we’ve been “eggs-perimenting” with eggs.  The first part is to create a Naked Egg.  WHAT??  Did I say NAKED??  Yes I did!  And that was enough to get the giggles going in our kitchen.  So simple.  Two ingredients that I know you have at home.

Here’s what you need to get started:

  • Eggs (At least 2 in case they break.  We used 4)
  • Vinegar
  • Clear Jars/Cups

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First I gave raw eggs to the superheroes to touch and observe.  Since mine are young, I had to ask them “probing questions” such as:

  • What color is it?
  • Is it bumpy or smooth?
  • Is it hard or soft?
  • What shape is it?

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Then we carefully added the eggs to the clear jars.  One egg per jar.  Add enough vinegar to cover the egg completely.  The eggs might float and leave the top uncovered.  This is okay.  You will most likely need to change out the vinegar the next day and you can invert it then.

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The superheroes immediately noticed the bubbles on the egg shells.  We talked about what that might be.  They asked if there was baking soda on the outside of the egg since they know that vinegar and baking soda creates bubbles.  I told them it was similar to baking soda but not quite. For those of you with older superheroes, baking soda is Sodium Bicarbonate and egg shells are mostly composed of Calcium Carbonate, both of which are bases that react when mixed with an acid such as vinegar (Acetic Acid).

We let the eggs sit overnight in the jars and observed them in the morning.  We started to notice a few things:

  • the eggs looked bigger
  • the egg shells were disappearing
  • there were lots of bubbles on the outside of the egg
  • the eggs looked yellower
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After 1 day, the shell is partially dissolved

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The froth on top is from the dissolved shell.

We discussed what was going on and the superheroes offered their own explanations. We carefully drained the jars of the vinegar and added fresh vinegar to continue to dissolve the shells.  I also gently rubbed on the eggs to scrape some of the shell off (it turns into a powder like coating that you can easily rub off) just to hurry up the process.  The eggs are very delicate at this stage as the only thing holding it together is a thin membrane. You might have noticed this thin membrane coating the inside of an egg shell when you crack them.  We DID end up losing an egg while draining one of the jars.  You can see the membrane floating at the top.

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After 3 days soaking in vinegar, this is what we ended up with.  A naked egg!

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A naked egg vs. a regular raw egg

And of course, the superheroes completed their observation sheets.

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The Science behind the Experiment:

There are a couple of things to note in this experiment.

First, and most obvious, is the dissolution of the egg shells.  As stated above, about 95% of an egg shell is composed of calcium carbonate which is a base.  When an acid like vinegar, also known as Acetic Acid, is added, the two chemicals neutralize each other, thus leading to the disappearance of the shell.  The bubbles that you see are carbonate ions from the shell that turn into carbon dioxide in this acid-base reaction.

Second is the obvious change in size of the eggs.  Once the shell disappears, a permeable membrane remains.  Permeable means that some substances can penetrate (or diffuse into) the membrane, such as water.  This process is called osmosis, the diffusion of water.  Many secondary teachers use this experiment to demonstrate how the membranes inside of our cells work.  (More on this in Part 2 of the Eggs-periment).

Follow this link for more details about this experiment:

http://www.exploratorium.edu/cooking/eggs/activity-naked.html