Which chemical symbol represents an element?

1. c20

2. co

3. h2o

4. h2co3

1.

Explanation:

Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Carbon

Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: carbon monoxide , water and hydrogen carbonate

Thus chemical symbol represents an element is