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

Directions:
  • 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
Matches
5 Tbsp vinegar
1/2 Tbsp baking soda

Directions:
  • 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

Directions:
  • 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?

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*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!

Sunday, November 3, 2013

Science Kiddo Camp

This past week we had our first session of our Science Kiddo Camp! It happened to be the day before Halloween, so the kids came dressed up in their costumes. We only did the most haunted, slimy, ooey, gooey chemistry experiments out there.
We made our Magic Bubbling Potion first thing. This was a great way to start our class since it's such an impressive, fun experiment, and so fitting for Halloween.
The kids were amazed to watch the Brain Eating Parasite dissolve their cups right before their eyes! One little boy mentioned after our class that they should put lemon essential oil into landfills to dissolve all the styrofoam. I think that is a brilliant idea!

We also did our Magic Inflating Balloon (we drew a witch on the balloon and called it our Witch's Brew). The brew bubbled up into the balloon, which made it so huge and heavy it fell over. The kids loved watching the balloon grow while we worked on our other experiments.

We made Lava Lamps, too. I didn't get a good picture of this, but they had a blast dropping in their Alka-Seltzer tablets and watching the bubbles fizz up and then fall back down.
The kids worked really hard on their science notebooks after each experiment. I loved seeing how each of them interpreted what they were observing into pictures in their notebook.
They LOVED their GAK! I was glad I saved this one for last because all they wanted to do was play with it once they made it, which was totally awesome :) I heard from parents afterward that the kiddos played with their GAK endlessly for days afterward.

Thanks for the awesome class! Next week we are switching gears to learn about electricity and magnetism. Stay tuned!

Saturday, November 2, 2013

Lava Lamp

Have you seen those magical lava lamps that captivate your attention by producing blobby-bubbles that rise and fall over and over again? Yeah, we can make one of those. And we can learn a whole lot about chemical mixtures while we do it.

Ready to make your own lava lamp using the brilliance of chemistry and some easy-to-find household materials? Let's get started!

Total Time: 5-10 minutes
Difficulty: Easy-Cheesy

Materials You Need:
Clear plastic or glass bottle
Vegetable oil (the cheaper, the better)
Water
Food coloring (if desired)
Alka-Seltzer tablets (or generic equivalent)

Directions:
  • Fill your bottle about 1/3 full of water.
  • Add food coloring, if desired. It's best to have a darker color so you can really see the water "bubbling" through the oil.
  • Fill your bottle the rest of the way with oil, being careful to leave at least 2 inches empty at the top.
  • Drop in an Alka-Seltzer tablet and watch what happens!
The chemistry behind this experiment is exactly the same as that of the Color Bombs Experiment we did a few weeks ago. Oil and water don't mix because they are made of different kinds of chemical bonds. Oil is nonpolar while water is polar, which means they will never mix, even when shaken extremely hard. Food coloring dissolves in water (since it is water-based and polar as well), which leaves the oil sitting on top by itself. When you drop an Alka-Seltzer tablet into the bottle, it only reacts in the water layer. Carbon dioxide bubbles are released as it reacts, causing the fun effect of colored water bubbling up through the oil, and then back down again. This reaction will occur for as long as you feed it fresh Alka-Seltzer tablets. After all the tablets have been used and the mixture stops bubbling, you can even store your lava lamp indefinitely for later use. Enjoy!

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