Thursday, April 17, 2014

How to Dye Eggs Naturally Using Acid/Base Chemistry

One of the things I anticipate most about this season is dying eggs with my family. It's one of those things that is always fun no matter how old you get. This year we added another fun dimension to our egg-dying party by incorporating acid/base chemistry into it. For those of you who love science AND love doing things naturally (even organically!), this is the perfect activity for you.
The star of this show is red cabbage. It contains a chemical called anthocyanin that changes color depending on the acidity of its environment. This means it is a pH-indicator, a gauge that tells you how acidic or basic the surrounding environment is. Red cabbage is purple in a pH-neutral environment, but it turns pink in an acidic environment and bluish-green in a basic environment. We recently did another experiment with red cabbage where we froze cabbage-water into ice cubes and tested the acidity of different solutions. It's the same chemistry, just a different way to see it.

Total Time: This experiment takes awhile, though you don't have to actively be doing anything for most of the time. Allow about 40 minutes to boil the eggs and cabbage and at least 12-18 hours for the eggs to sit in the fridge in the cabbage solution. Painting the eggs only takes 10-20 minutes at the end.
Safety Concerns: As always, be careful when boiling things with kids around. Use caution when cooking and handling the hot eggs and cabbage.

Materials You Need:
One half of a head of red cabbage
One dozen large eggs
Slotted spoon
Lemon juice or vinegar
Baking soda
Q-tips or paint brushes to paint the eggs

To prepare the eggs:
  1. Place eggs in a large pot in a single layer.
  2. Chop up your cabbage into small pieces and throw them into the pot with the eggs. Add enough cold water to cover everything by one inch.
  3. Bring the cabbage/eggs/water mixture to a boil. Remove from burner and cover the pot.
  4. Let your mixture stand for about 12 minutes for large eggs (9 minutes for medium eggs, 15 minutes for extra large eggs).
  5. Using a slotted spoon, remove your eggs from the pot and cool completely under cold running water or in a bowl of ice water. They will most likely still be very white at this point.
  6. Refrigerate your eggs. Once your cabbage water has cooled to room temperature, place your eggs back into the pot and refrigerate everything together. Make sure the eggs are completely submerged in the water for best color.
  7. Leave your mixture in the refrigerator overnight.
 To paint your eggs:
  1. Use a spoon to scoop your eggs out of the cabbage mixture. Feel free to rinse them off and pat them dry. They should be some shade of bluish-purple (depending on how acidic your tap water is!).
  2. Pour some lemon juice or vinegar into a small cup (this is your acid).
  3. In another cup mix 1/2 tsp baking soda with enough water to dissolve it (this is your base).
  4. Using your Q-tips or paint brushes, paint your eggs! Watch as your eggs change from blue to pink when you paint with lemon juice and from blue to greenish-blue when you paint with your baking soda solution (this may not show up well until the eggs are dry again).
  5. Feel free to try painting your eggs with other solutions from around the house to see what happens. Some ideas to try are washing soda, cream of tartar, and antacids. If your egg turns pink you know the solution is acidic, if it turns green you know it's basic!
Something interesting that I noted was that the cabbage solution turned out very blue this time, whereas last time we did this experiment it was beet red. We moved to a different county since last time, so does that mean our drinking water is more basic on this end of the city? Or is it a difference in the cabbage I purchased each time? I don't know, but I think it's definitely worth finding out!

Print These Instructions
You can see the whitish-pink spots where we painted with lemon juice. On the right of the egg you can see it's a little bit green, which is where we painted with baking soda.
Thanks to the Kitchen Pantry Scientist for this awesome idea!

Wednesday, April 16, 2014

DIY Window Gel Clings

Window gel stickers? Window jellies? Window gels? I really don't know what they are called, but my kids love them. How would you like to make your own gel clings that are not only cute, but also edible? I thought so.

Now before you think I have gone too artsy on the Science Kiddo, just stay tuned. There is a ton of science your kids can learn from this in addition to it being a great creative outlet and fun activity for you to do as a family.

It's really simple and only takes a few ingredients. Our window jellies turned out beautiful and fun, just in time to catch the sun's warm spring rays in our window.

Total Time: About 20-30 minutes
Safety Concerns: You will need to boil water for this. Just watch your kids around hot water and the resulting hot gelatin. Let it cool a bit before your kids get close.

Materials You Need:

Four cups of boiling water
Six packets of unflavored gelatin
Food coloring and glitter of your choice
A toothpick
One large cookie sheet with a rim or two 9 x 13 casserole dishes
Cookie cutters


  • Add the gelatin to the hot water. Stir to make sure it all dissolves and spoon out any bubbles.
  • Pour your mixture into whatever containers you want. You want it to be about half an inch thick. It doesn't have to be exact, but it is best if it is level. Bowls won't work very well since the gelatin won't be a uniform depth.
  • Once gelatin is cooled a bit, but before it hardens (you have about a 45-minute window here) have fun dropping food coloring into your gel and swirling it around with your toothpick. Sprinkle it with glitter if you desire.
  • Let the gelatin harden. It should only take 30-60 minutes. Since it's super-concentrated it hardens quickly without being in the refrigerator.
  • Once it has set use cookie cutters to cut out shapes or cut out your own shapes using a butter knife.
  • Use a spatula to lift your gel shapes out of the pan. Don't worry if they tear because you can simply mold them back together. Stick them to your windows and enjoy!
Print These Instructions

Easy, right? One thing I love about decorating the gelatin is that it is much more viscous, or thicker, than water. This means that you can decorate each corner differently and the colors/glitter won't run into each other. You can customize the colors and shapes for whatever holiday or season you want!

If you want to incorporate more science into this activity you could pour some water into a pan, drop colors into it, and compare how it behaves differently from the gelatin mixture. Then do the same thing with vegetable oil. (We did this in our Color Bombs experiment.) You could also observe how your window gels evaporate after a few days on the window, leaving behind paper-thin dry shapes.
Note: You probably won't be able to take these jellies off your window and put them back on more than a few times before they tear beyond repair. They are slightly more delicate than the window gels you buy at the dollar store.

Wednesday, April 9, 2014

Which One Will Freeze the Fastest?

This article was contributed by Jen, a homeschooling mom of three from Beaverton, Oregon. In February the Portland area was hit by a huge snowstorm for these parts and the entire city basically shut down. Jen did this awesome experiment with her kids while they were hunkered down at home.

We took advantage of the snow storm and subfreezing temperature in February to have a little Science Snow Fun! What we did was fill balloons (and a few random party bags) up with water, added some food coloring, and laid them out in different locations outside. 

You’ll see the bags and a balloon on our back deck:
And a few balloons set up on/around a table in the backyard. Will had a clever idea to suspend one balloon from the table itself - see the light blue balloon in the picture below :)
Enter the hypothesis!! We guessed that the balloon suspended in the cold air would freeze the best, as the balloons surrounded by snow (not unlike a snow cave) would stay closer to the 32 degree mark. We weren’t sure how much the wood from the deck would affect the balloons.

In all fairness, to have a truly scientific experiment, we should have filled the balloons all the same size, but without a hose, we were just lucky to get the water in the balloon in the first place :) 

We waited overnight - and then examined each of our balloons/bags.

The bags up on the deck formed crystals, but were mostly liquid:
This was the balloon that had its own snow cave…. Logan is going to open it up… and you’ll see the lesson we learned the hard way: don’t dye balloons with red food coloring…
Not a good choice of color… sorry :(

Moving on!! Here’s Logan taking down the balloon from the table - check out how much snow is actually ON the table!!! 
The balloon that was suspended from the air was the ice “balloon” on the right. The one on the left was a balloon that was on the table, BUT did not have a snow cave around it to keep it “warm” and so it too because an ice balloon :) 
Conclusion: The balloon on the metal table and the one hanging from it froze the best. The balloon and bags that were sitting on the wooden deck hardly froze at all. We think this is because the balloons on the table received cold circulating air from all sides. Plus, metal is a better conductor than wood, meaning that the balloon on the metal table got colder than the balloon that was sitting on the wooden deck.
So much fun!!

I love that Jen and her kids used their time at home to have some fun, ask some scientific questions, and discover some new things together. What are some scientific things your family has learned this winter?

Tuesday, April 8, 2014

Magic Balloon Bottle

We love to blow things up around here. But what about sucking things in? This is an experiment that often surprises the kiddos because they don't often get to see a balloon get pulled inside out. Ready to startle the kids? Let's get started.

Total Time: About 10-15 minutes
Safety Concerns: Be careful around hot water. At one point the glass bottle does get warm from the hot water, so just make sure that it's not so hot as to burn fingers. Use oven mits if necessary.

Materials You Need:
A glass bottle
Warm water
A balloon with the neck cut off (This is apparently necessary. We tried it several times without cutting the neck off and it didn't work.)
Large bowl full of ice water

  • Fill the glass bottle with warm water. We heated the water up on the stove and then poured it into the bottle, but hot tap water is probably fine, too. No need to use boiling hot water. See Safety Concerns above.
  • Leave the bottle for a few minutes so that it gets warm. Pour out the water.
  • Stretch the balloon over the top of the bottle.
  • Stand the bottle in the bowl of cold water.
  • What happens to the balloon?
So what is going on here?

When air is heated up the molecules in the air have more energy to bounce around. This increases the pressure, or expands the air. When air gets colder the molecules slow down and move less, which decreases the pressure and makes the air contract, or get smaller.

In this experiment we first filled the bottle with warm water, which heated up the bottle and the air inside. As we cooled the bottle down, the air inside cooled down and contracted, or took up less space. To make up the extra room in the bottle, air from outside pushed into the bottle, which pushed the balloon into the bottle as well. Another way to explain this is to say that we created a vacuum in the bottle, which sucked the balloon into it.

Cool, right? Try this with different sized containers, get really scientific and use a thermometer to measure the temperature of the water, or keep track of how long you need to cool down the bottle before the balloon gets sucked into it. Have fun!

Print These Instructions

Wednesday, April 2, 2014

Science Kiddo Expo - Spring 2014

This week we did two big Science Kiddo Expo days to promote the importance of science learning for young children. It couldn't have gone any better! Thank you to the Harrison Hill Swap 'n' Play for hosting us and for everyone who brought their kids and participated. We all had a fantastic time playing and learning science.

Here are a few of the highlights:

Of course we had to do our most impressive demo with dry ice, water, and tons of bubbles! This is always a huge hit. The kids couldn't keep their hands out of it!
Using baking soda and vinegar to blow up a balloon
Learning about the balance
We also did the magic inside-out-balloon, had loads of fun with magnets, went fishing for ice, and blasted balloon rockets. So fun!

Tuesday, March 11, 2014

Make Your Own Fire Extinguisher

Have you ever sat around a campfire and watched it dance and glow? Have you ever wondered about the properties of fire? We know it is hot. We know it needs something to burn, like paper or wood. We know it is usually orange or yellow, depending on the materials that are being burned. And we know that it needs oxygen to "stay alive".

There are several different ways to deprive a fire of oxygen so that it will go out. You can dump water on it. You can put something like dirt or sand on top of it. For small fires, like candles and matches, you can simply just blow on it.

So why does a candle go out when you blow on it? One of the possible explanations is that when you exhale you breathe out a lot of carbon dioxide. That carbon dioxide displaces the oxygen around the fire, making it go out. Some fire extinguishers even use carbon dioxide (among other chemicals) to put out larger fires.

In this experiment we made our own fire extinguisher using vinegar and baking soda. The reaction of these two materials produces carbon dioxide, which you can see bubbling up through the solution. Carbon dioxide is heavier than air so it drops right on top of our candle to put the flame out.
This experiment can be found in The Usborne Science Encyclopedia, one book that I consider essential in our home library and one of our favorites.

Total Time: About 5 minutes
Safety Concerns: Use caution around fire and matches. Make sure your child understands that playing with fire is dangerous and that he or she can get burned severely, even with small candle fires.

Materials You Need:
A sturdy bottle (preferably glass)
A funnel
A small candle
5 Tbsp vinegar
1/2 Tbsp baking soda

  • Have an adult light the candle.
  • Add vinegar to your bottle.
  • Using a funnel, quickly drop the baking soda into the bottle.
  • Being careful not to spill your mixture, hold the bottle at an angle so the carbon dioxide can flow out onto the fire.
Print These Instructions

Sunday, February 9, 2014

Don't Eat the Yellow Snow, but the Blue Stuff is Probably Fine

This week we got hit with a major snowstorm for these parts. Because Portland doesn't own more that a handful of snowplows we have been stuck inside for three straight days now. Lucky for you, we have been doing lots of fun experiments with the snow to stay entertained!

It's cold outside, so we opted to bring the snow in rather than take our bodies out. We gathered up our ice cube trays and some food coloring and we were good to go.
Place some snow in each ice cube compartment and then add 1-2 drops of food coloring of your choice. Mix and match colors to see what happens as the snow melts!
This is a great experiment for a few reasons. First, it shows the child that snow is in fact frozen water. We always teach them this, but it's always so surprising when they actually see it for themselves. Second, it illustrates what happens when two colors mix. The child can see for themselves that they added one drop of red and one drop of blue, and as the snow melts they will see purple water. Finally, it's a fun and easy experiment that even got me excited that there was snow on the ground.

What other fun experiments are you doing this winter?

Monday, November 11, 2013

Fishing For Ice

Have you ever lived in or visited a snowy place in the winter? Have you ever wondered why salt is spread over the roads after it snows or why people sprinkle salt over their stairs and walkway when they get icy? Well wonder no more because we are going to answer those very questions right now.

When salt is mixed with ice it lowers the freezing point. Usually water freezes at 32° F (0° C), but when it is mixed with salt it lowers the freezing point significantly. This simply means the ice melts.

For our experiment today we will use this phenomenon to do a little trick I like to call "Fishing for Ice".
Total Time: Less than 5 minutes
Difficulty: This may be the easiest experiment we have done so far, which is saying a lot since most of our experiments are very easy.

Materials You Need:
Cup full of water
A few ice cubes
Table salt
A piece of string

  • Place the ice cubes in the cup of water. They will float on top.
  • Try to "fish" for an ice cube with the string. It won't "catch" anything.
  • Place the string in the water and across the top of the ice cubes. 
  • Now sprinkle a little bit of salt across the ice cubes. Wait for a minute or so.
  • Pull the string out and see what you caught!
When salt is sprinkled over ice it melts. However, when it is used in such a small amount, like in our experiment, the water around the ice freezes again quickly. This means that the string gets trapped as the water around it freezes, thus making it stick to the ice. We were able to freeze all of our ice cubes to one piece of string. How about you?

Print These Instructions

*Note: In the video we put salt in first and then tried to "fish" with the string. It may work better if you put the string across the ice cubes first and then sprinkle some salt on top of the ice and the string, as mentioned in the directions. Let us know how it works for you!