The ozone hole, chemistryland and interactive tutorials

The ozone hole 

Everything you ever wanted to know about ozone, the layer and its hole is to be found at this informative and easily navigable site. The information presented here can be trusted given that it is compiled by the British Antarctic Survey, NASA and other well-respected scientific bodies. There is information about ozone itself, both good and bad varieties, Dobson Units, CFCs, plus discussions on climate change. If you are teaching a topic that includes the ozone hole, look here first for background information.