 So as we've already talked about Charles' law, it states that there is a direct relationship between volume and temperature of a gas. So what we want to do is we want to show this direct relationship by decreasing the temperature of the gas in this balloon here. We're going to do that using liquid nitrogen. Liquid nitrogen at a temperature of negative 196 degrees Celsius will decrease the temperature of the gas in the balloon. Let's see what happens to volume. As you can see, the volume of the gas in the balloon decreased when temperature was also decreased. As the temperature of the balloon starts to increase back to its normal room temperature, you see that it goes back to the original volume.