Answer:
18 molecules of oxygen or o2
Explanation:
Because a carbon dioxide molecule has 2 oxygen molecules and 1 carbon molecule, this would mean that, to make 9 co2 molecules, you would need
18 because 9x2 is 18 molecules of 02
and for carbon molecules its literally 9 because for just 1
co2 it contains 1 carbon molecule
hope this helped