Respuesta :

Answer:

co2 is a compound.

Explanation:

Oxygen(O) is an element having atomic number 8 and mass number 16.

Carbondioxide is a compound formed by burning of carbon and organic compound and it is a colorless and odorless gas.

O2  is the molecular form of Oxygen.

Cobalt(Co) is an element having atomic number 27 and mass number 59.