| Term: | opacity |
| Definition: | the condition of lacking transparency or translucence; opaqueness |
| Examples: | A chronically high opacity level may be one characteristic of a polluted stream. |
| Term: | opacity |
| Definition: |
The extinction coefficient for a particular substance is a measure of how well it scatters and absorbs electromagnetic radiation (EM waves). If the EM wave can pass through very easily, the material has a low extinction coefficient. Conversely, if the radiation hardly penetrates the material, but rather quickly becomes extinct within it, the extinction coefficient is high. |