Danish pupils are examining the different gasses of the atmosphere.

We talk about an examine O2, N2, CO2, and H2. We also talk about the origin of O2 and the use of CO2 in photosynthesis. 

The first trick is to keep the gasses pure. 

In order to do that, I give the pupils a portion of the gas in a bag. I use urin bags from the hospital. (New ones) The pupils then fill the gas into a test tube using a bowl of water. The tube must be full of water first.

When vi have the gas in the tube we can make an experiment with it. 

In the boxes, you can see 6 different experiments.

Is it flammable?

is it oxidizing? Can it enhance a fiery reaction?

Does it have a color?

Is the gas lighter or heavier than regular air? (Difficult, better for older students or the teacher. You have to keep very still and in order to detect the gasses you have to use different techniques)

And the two last experiments are just testing whether or not the gas is carbon dioxide.

The last picture shows how you use a CO2 indicator. If you do not have an indicator, you can use a solution of Ca(OH)2, as shown in the second to last picture, it will become cloudy if CO2 is present.

All of these experiments are very save but the Ca(OH)2 can irritate the eyes and stain clothes. 

Have fun Norway can Use their wonderful Science room. Naturfag.

Regards Troels

Did flowers need water? And can we see it?