What is the ozone layer and what does it do?
LEVEL: Intermediate
To find a good, basic, defintion of the ozone layer we started with one of our favourite kid-friendly search sites: Factmonster. Just type ozone layer in the search box (top right hand corner of the home page) and you'll get a list of results from dictionaries, encyclopedias and online articles.
There's a good introduction to the depletion of the ozone layer with diagrams and links, at Science by Slim.