Why does carbon dioxide diffuse accross the lung membrane so glibly (moreso than oxygen)?

Why does carbon dioxide diffuse accross the lung membrane so glibly (moreso than oxygen)?
Please see the web page for more details on Carboxyhemoglobin. Carboxyhemoglobin is hemoglobin bound to carbon monoxide instead of oxygen or carbon dioxide. Carbon monoxide have a much higher affinity for hemoglobin than does oxygen (210 times more), and soaring percentages of carboxyhemoglobin surrounded by the blood impairs the run of the mill transport of oxygen by the blood.
If I remember right, carbon is fairly small and oxygen is bigger
Basically the red blood cell like CO better later O2. Most sources say the CO have 800 times the affinity (the force of attraction between chemical species) for the red blood cells next oxygen. So CO is 800 times more likely after oxygen to "jump" on to the blood. I hope this helps.
http://www.elmhurst.edu/~chm/vchembook/2...
Although I agree beside Matt I'll put it in simple lingo. Carbon Dioxide is lighter and more permeable than Oxygen thats why it diffuses so much easier.