Scientific Tutor

What is the Kinetic Molecular Theory?

This is a review of the subject but for a more complete explanation also check out the molecules and states of matter section in the states of matter lesson. To understand gasses, we must first understand what is called the kinetic molecular theory. What is the kinetic molecular theory? Let us break down the phrase. KIN means movement, MOLECUL means molecule. It is a theory of how molecules move. This happens for all molecules, but is most easily understood in a gas. Imagine if you and 2000 of your friends each had a soccer ball on a smooth surface like a small iced over lake. If all of you stood around the edge of the lake in a circle and kicked your soccer ball into the middle of the lake and then kept kicking every soccer ball that came your way back into the middle of the lake. That would be how the molecules of air are acting in the air around you. They would move across the lake and bump into each other and bounce or travel toward the outer edge. The only difference between the lake example and air molecules is that in the lake example we are demonstrating what is looks like in 2 dimensions. In reality molecules in the air bounce around in 3 dimensions. I have found the best way to imagine the reality of how air moves is think about it inside a container like a balloon. All the air molecules are bouncing around inside balloon like little soccer balls. They hit each other they hit the inside walls the balloon container and they just keep bouncing around. From the visualization of the kinetic molecular theory, we can begin to ask how is the way that gases behave reflected in gas law formulas?