Which of the following is an example of an element?

A.  
H2O (water)

 B.
fire

 C.
CO2 (carbon dioxide)

 D.
C6H12O6 (glucose sugar)

 E.
O2 (oxygen)

Roger the Mole2020-11-11T20:57:47Z

O2 (oxygen) 

cmac'm: The question did not ask about atoms vs molecules.  Oxygen is an element, period.