Wednesday, 30 April 2014

Learning about weather

We have been working to understand air pressure in our science lessons and attempted a few experiments
the first one we tried was using cold water and coloring it blue

using card stock we were able to turn it over and with some careful effort 

Let go and see the pressure of the card holding up the water.  We watched this done on a Bill Nye video on pressure and recreated in our home

Next we tried another experiment from Bill Nye that didn't work out so great for us.  we took a  jar of hot water and color it red and then take a second jar of cold water and color it blue

the point of the experiment was to show that hot air (water in this case) remains on top and the cold air (water) remains at the bottom which is how weather fronts are formed and how storm systems emerge.

We had a very hard time getting the jars to line up and the card stock would not slid out in one go which caused a problem with equalizing the pressure

and this experiment was a complete fail, while it worked on the video it did not work for us:(  We know this because the water instantly mixed together turning purple when it should have stayed red on top and blue on the bottom.
But then I found another experiment that had the same principal but went about it slightly differently and it worked out so much better:)  I found this one on the kitchen chemist site
we colored two glasses of hot water red and filled two glasses with cold water.  Notice the water is completely to the top of the glass

Next we took two discs that were old and not being used 

and stacked them together covering the small hole 

and placed it on top of the hot water glass

very slowly we slide the CDs together and watched

while a small amount of red seeped thru the majority remained on top

Hence seeing that the hot air (water in this case) is less dense than the cold water...this remained so until the two waters became the same tempture and then they mixed

Next we took the cold water and using the same method and placed it on top of the hot water and slid the CDs together and watch instantly as the hot water seeped into the cold water until both glasses where completely red.
Next we tried two more experiments from the Kitchen chemist which showed hot air rising.
Take your toaster and use two cereal boxes to wrap around it

cut out a slight hole so you can reach the levers in the  toaster and  set it at about medium temperature.  The highest setting melted the plastic

Next carefully placed a plastic bag over the cereal boxes and gently hold and turn on the toaster and watch as the bag fills with hot air

Then let go and watch the bag rise up just like a hot air balloon:)
 I think the kids got the point of hot air rises but since we love experiments we tried one more that the kitchen chemist recommended:)

take a tea bag that has a string and undo the string carefully

unfold the teabag and empty out the tea

Place the empty cylinder tea bag upright onto a plate and light it on fire

watch carefully as it burns because as soon as it reaches the bottom

It lifts off the plate, luckily it turns to ashes before it hits the ceiling:)  

 We had fun finding experiments that demonstrated that hot air rises and is less dense than cold air this is important as we discuss weather fronts and how weather is formed


  1. It sounds like the kitchen chemist is the place to go for science experiment ideas! Some great hands-on leaning going on at your place!

  2. I loved these experiments. I like the hands on learning. My daughter who home schools is coming for several weeks to stay with us before she moved to Australia in July. I think I will have her look at this one and try it. I have missed reading your adventures.
    Thanks for the lesson and blessings to you!