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)
or
(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!

Pulleys

 

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.

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