Answer:
The purpose of a map key is to tell you the meaning of the symbols on a map. The key on a map interprets each symbol so that you can read and understand the map. ... The map key is the only way for you to know for sure what the above symbol means.
It is a visual explanation of the symbols used on the map. I hope this helps
Picture below
Carbon, Oxygen, and Nitrogen
to make is visuable
Explanation:
