Question

Which chemical symbol represents an element?

1. C20


2. CO


3. H2O


4. H2CO3

Answer 1

C20

Step-by-step explanation:

All the other options are compounds because they have more than one element in them.

Answer 2

Answer: 1.
`C_(20)`

Step-by-step 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
`C_(20)`

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
`(CO)` , water
`(H_2O)` and hydrogen carbonate
`(H_2CO_3)`

Thus chemical symbol represents an element is
`C_(20)`