Subject: Why does the ozone form a 'layer' in the atmosphere?

From Dalton's law of partial pressures,it is clear that a gas occupies the 
entire space available to it,whatever may its atomic weight be.Thus,the other 
gases present in the container do not hinder the gas to occupy the entire volume
of the container by Brownian movement.so,is there any other force acting on 
ozone to stop it from reahing the Earth's surface?As since ozone's molecular 
weight(48)is much greater than the average molecular weight of air 

Re: Why does the ozone form a 'layer' in the atmosphere?