Motivating Moms to become science teachers to their children

Archive for the ‘Experiment’ Category

Float or sink experiment with balloons

My son asked me to blow up a balloon to see if it would float or sink, and he wanted to test it while playing in the tub. Sure, why not! He noticed right away that the balloon floated completely above water. He wanted to see if he could make it sink so he pushed really hard on the balloon but it kept floating and escaping from him hands as it slipped away.

Sink or float balloonsAt that point, I filled a balloon with water and asked him to repeat his experiment. The balloon still floated as it did not touch the bottom, but the of the balloon was immersed under water, and it was very easy for my son to push on it to make it go even further in the water.

This kids science experiment was a great opportunity to talk about the word “density”. Something that is more dense, like water, will sink more easily than something that is less dense, like air.

This experiment is definitely worth a try. It is cost effective, quick to set up, easy and provides a whole lot of fun during and after the experiment itself. Enjoy.

Click here to see our float or sink experiment using fruit.

2 ways to get “dancing raisins”

The “dancing raisins” experiment is so easy that I cannot believe it took us so long to give it a try. All you need to do is place a few raisins in a clear carbonated drink and voila! The raisins appear to be dancing as they get displaced up and down due to the bubbles of the drink. Note that we used Ginger ale because that is all we had available at the time, so the liquid appears a bit darker. It is not the raisins that discolored it.

Then we placed some raisins in a glass with plain tap water afterwards. If you try this experiment with your little ones, ask them what they think will happen this time. If they understood your explanation of the gas bubbles, they should be able to observe that there are no gas bubbles in plain water and thus the raisins will just sink.

Dancing raisins

Give them a straw and let them make their own bubbles in the water. The kids can get the raisins to dance with their own bubbles, and it’s a time when they are finally allowed to make bubbles in a glass with a straw. If you feel like delving into some physiology while you are at it, ask them where they are getting their ‘gas’ from to make the bubbles and you can start a discussion on their lungs and air.

Dancing raisins in water with a straw

Testing diapers to learn about absorbency

We set up 3 glasses with different water volumes (with blue food coloring), each representing the amount that a child’s bladder can hold depending on their age; 2, 4 and 6 years old.  To calculate how much urine a child’s bladder can hold based on their age, take a look at my post “This is how much pee your bladder holds”.

diaper absorption testWe poured the water from each glass into an individual diaper.  Many observations were made by my children.  It was impressive to see how quickly the diaper absorbed the liquid.  For the first few seconds, it seems as though the liquid will spill over.  The diaper’s absorbent material absorbed so much water that the thickness of the absorbent layer increased substantially.  If we were to redo this experiment, we would measure the before and after thickness of the absorbent layer.

Then, we cut open a dry diaper and compared its content with the content of the wet diapers.  We observed 2 types of materials from the dry diaper; cotton-like material and white grainy content.  The tiny grains are sodium polyacrylate, the super absorbent polymer used in most diapers.  This polymer is so absorbent that it can absorb about 200 times its own weight in water.  We certainly observed this when we cut through the wet diapers.  No wonder some of these diapers claim that they can keep a child dry for up to 12 hours!

Super absorbent polymer in diapers

This is how much pee your bladder holds

This experiment started off simply because we had a few extra unused diapers lying around, and I wanted to show the kids how the absorbent material in a diaper can absorb a lot of water.  Learn more by clicking on “Testing diapers to learn about absorbency”. But the kids actually got a much bigger kick out of seeing approximately how much pee their bladders can hold.  We used water with blue food coloring to represent the urine.  We estimated the volume of urine per bladder for a 2 year old, a 4 year old and a 6 year old.

As per the Brenner Children’s Hospital, we calculated the volume of urine per bladder for the different ages with the following equation:

AGE + 2 = BLADDER CAPACITY (in ounces)
(AGE + 2)30 = BLADDER CAPACITY (in milliliters/cubic centimeters)


Urine in bladder per age - smaller

After looking at the difference in volume per age, my kids realized that their bladders are all different sizes and as such they can each hold a different amount of urine.  This also opened up the discussion that when children grow, not only do their bones and muscles grow, but internal parts do as well.

Here are a few kid-friendly videos that explain how the bladder works:

Human Body Parts for Kids: Bladder

About Kids Health:  Kidneys and bladder (a very short anatomical animation)

A journey through the nephron

Excretory system by Make Me Genius

Urinary system by Brain Pop

Valentine candy in ice balloons

Ice balloon with Valentine candy Ice balloon with Valentine candy Ice balloon with Valentine candy

We made more ice balloons during the last cold spell, but we wanted to make them differently.  So this time, we did not add any food coloring.  Instead, we added a different type of Valentine candy in each and used plain tap water.

IMG_3417We used 3 different types of candy: jelly heart candies (pink and red), hard heart candies (red), and sweet and sour candies (pale colors).

Both the jelly heart candies and the hard heart candies naturally added their red dye to the ice balloon.  Also, both contained oil in their ingredients, therefore the oil separated from the water and did not freeze.  So use a deep dish if you plan on freezing ice balloons with these types of candies.  The hard heart candies completely dissolved.  The jelly heart candies kept their shape, but lost much of their color and their texture changed substantially.  The sweet and sour candies became very mushy.

The kids were intrigued to see the ice balloons melt because they could not wait to see what had happened to the candy.  This experiment is worth trying for the sake of observation.

Pulley fun for kids

After watching this video on pulleys (by Make Me Genius), we decided to set one up in the backyard for our kids.  We did not have an actual wheel with raised edges on both sides (to avoid the rope from slipping out), but we were able to find a ferris wheel toy that did the trick.  It was not perfect, as the step at the bottom of the toy sometimes got in the way of the rope winding around the wheel properly.  It did not really matter though, as our children got the idea of what makes a pulley and why pulleys are important.  Objective achieved!



DISCLAIMER: I am not a scientist. I am not a teacher. I am a resourceful Mom with a science background who is passionate about teaching sciences to her kids. Although this blog does its best to use scientifically accurate terms and concepts, the main focus is to initiate a curiosity and an interest about sciences in children. Therefore, concepts and terms may be greatly simplified and/or only discussed in part.

Water absorption experiment with a twist

I remember doing the ‘creeping’ water absorption experiment when I was a child, and it was so interesting to see the water transfer from one glass to the other until the water levels in both glasses were equal.  We have done this experiment with our kids several times, so when they asked to do it again, we did it a bit differently.  This time, we used 3 different materials (plain white printing non-glossy paper, a cotton sock and a face cloth) to see which would absorb faster.  I explained to my kids that the material that would absorb the most would probably be the best to use when picking up spilled water or milk, so which of the 3 materials would be ideal for cleaning up such a mess.  Not surprisingly, the plain white paper absorbed the least (in fact it barely absorbed anything at all), the cotton sock absorbed in a similar fashion as how kitchen paper towels would, and the face cloth absorbed so much that it barely allowed any water to make it to the other glass.


Absorption comparison


DISCLAIMER: I am not a scientist. I am not a teacher. I am a resourceful Mom with a science background who is passionate about teaching sciences to her kids. Although this blog does its best to use scientifically accurate terms and concepts, the main focus is to initiate a curiosity and an interest about sciences in children. Therefore, concepts and terms may be greatly simplified and/or only discussed in part.

Jelly worm osmosis experiment for kids

Jelly worm osmosisInspired by the gummy bear osmosis experiment, we did an experiment to see what would happen if we soaked a jelly worm in plain water, in water with salt and then in water with sugar.  We let the jelly worms soak for about 2 hours before measuring the results.

All jelly worms started off at approximately 10 cm, and they all expanded both in length an width after being soaked.  The one that was in plain water gained the most in length, whereas the ones in water with salt and water with sugar gained less in length, and their gain was similar to one another.

What we will do differently next time:  Instead of just using new jelly worms, we will take the expanded gummy bears and we will soak them in salted water to see if they end up shrinking.   We also probably left the jelly worms in their water solutions for too long as they were becoming quite soft and difficult to maintain as one whole piece.

Here are a couple of videos / animations that show the principles of osmosis:

How osmosis works
Osmosis and diffusion

And if you really want to hammer home the message on osmosis, there are other osmosis activities that you can try with your children.

7 Valentines Day science activities

11599724_sHappy Valentines Day !  Here’s a list of 7 science activities for Valentines:

  1. Vinegar hearts
  2. Puddle of chocolate kisses (you have to pay to get the full details on this activity, but I think enough information is provided to inspire anybody to come up with their own follow-up to this activity)
  3. Science sparks
  4. Love potions
  5. Dancing hearts (a variation of the Love potions mentioned above)
  6. Dissolving hearts
  7. Base / Acid hearts (Steve Spangler)

4 homeschooling snow activities

We were hit with a big snowstorm today.  What a great opportunity to teach preschoolers as much as possible about snow.  Here is a list of all our learning activities today:

1) Measuring snowfall:

We took an empty, transparent container and wrote the time at the bottom.  We then put this container outside and let Mother Nature take its course.  Every once in a while, we took a look to see how much snow was in our container.  It took Mother Nature a bit over 6 hours to fill our container with 16 cm of snow.  That’s a lot of snow.

Key learnings:

  • Snowfall is measured in cm (at least it is in Canada)
  • The meteorologists predict snowfall as best as they can, but it’s not until the snow actually falls that you can measure how much snow actually came down

For those of you who are keen on doing a more appropriate snowfall measure, take a look National Weather Service from Jackson KY website.  They describe how they ask their volunteers to measure snowfall.

Collecting snow and measuring at different times

2) What happens when snow melts:

We took 2 empty containers that had cup measurements inscribed on one of their sides.  We filled them both to the rim with snow.  We brought one on the kitchen table and we put the other in the freezer.  My oldest son knew it would melt and turn to water, but he thought the water level would be as high as the snow level.  At first, little fingers could not be stopped from touching the snow which was quickly followed with remarks about the coldness of the snow.

After about 30 minutes, it was evident just by looking at the container on the table that the snow was melting and the volume was decreasing.  I kept pointing out the water and the measurements to my kids.  We started off with 10 cups of fluffy snow.  We ended up with 1 1/2 cups of water.  Many sources, including Environment Canada, suggest that snow measurement vs. melted water measurement (in cm) is roughly a 10:1 ratio.

kids holding hands in snowI tried to explain this by stating that fluffy snow is like friends holding hands, but staying at arms’ length from one another, but that when it melts, all these friends then huddle together very closely.  You still have the same amount of friends, they are just behaving differently.  It went way over everybody’s head so we just kept moving on.  But I think I’m onto something with this explanation and I wrote it here intentionally so that I can remember to use it again next year.  We’ll see if it has more impact then or not.

The snow in our freezer remained relatively unchanged.

Key learnings:

  • When snow melts, it turns to water.
  • Snow melts in warm environments (like a heated house), but not in cold environments (like outside on a cold winter day)
  • The water level of melted snow is much smaller than that original snow level

Snow 10 cups melts to water 2 cups

3.  What do snowflakes look like:

Before doing this experiment, I sprinkled a black sheet of felt with a bit of water and put the felt in the freezer for about 30 minutes.  Then my son took the sheet of felt and held it outside to collect falling snow.  We then brought it in to see if we could spot any snowflakes.  We used a magnifying glass, which my kids found really fun.  We saw a few well-formed snowflakes.

Key learnings:

  • Sometimes rain comes from clouds, but when it is really cold, these rain droplets turn into little ice particles that come together to form snowflakes.
  • Each snowflake is a bit different from the other, even if we cannot see these differences with our eyes.
  • We learned the meaning of the word “contrast” when we discussed why we used the black felt sheet to better see the white snowflakes.

Here is a cool video that shows the formation of snowflakes, a website that details all the different types of snowflake shapes, and and an animation that explains how temperature can change snow to sleet, freezing rain or just rain. Click on ‘continue to active figure’ to see the animation.

Snowflakes caught on black felt

4.  Snowflake craft activity:

paper snowflakesWe just cut a circle and folded it onto itself a few times and cut out some shapes.  My kids had never done that, so they were quite amazed at the results.  The kids wanted to give their paper snowflakes a feeling of being real, so we stuck them on a window that was right in front of a snow-covered tree.  It makes the image a bit hard to see, but we captured the intent for the kids.

Key learning:

  • We learned the meaning of the word “symmetry”.

Now that the storm seems to have settled, tomorrow will be all about playtime in the snow: snow angels, snowmen, sledding, digging snow tunnels, and maybe a bit of snow painting if time permits.


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