http://www.naturegrid.org.uk/eco-exp/glossary.html
| Atmosphere | This is the layer of air surrounding the earth. The two main gases in the atmosphere are oxygen and nitrogen, there are also small amounts of carbon dioxide. |
| Biodegradable | Describes something which will rot naturally through the activity of decay organisms (e.g. decomposers). For example a fallen tree will biodegrade but a plastic bag will not. |
| Community | The people and groups within an area who have something in common with each other. For example you are part of a school community, but you may also be part of other communities such as a religious group or a neighbourhood group. |