“Air has mass. Air takes up space.” These two major principles are repeated over and over again in my classroom, because the idea that gas is matter and not just ‘invisible stuff’ is what I want to stress to my students before moving too far into section 1.5.
I like to get them excited about each section, and for this one I began by taking out my air cannon and firing it around the room. In an instant, attention is captured, and the pleas of students wanting to be hit by a blast of air is hard to contain! This, along with the demonstrations using the scale (another great chance to teach about scientific equipment!), helps to show that gas is matter.
To show how gases react when they are heated and cooled, I can think of no better experiment than making film bubbles on the bottle, and then heating and cooling the air inside the bubble. Students are fascinated, and always want to video record their activity, to which I gladly oblige. However, there is one problem I’ve always encountered, and for which I would gladly take any advice you can give.
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