Find the Oxidation Numbers 3CO_2

$3 C O_{2}$

Step 1

Since $C$ is in column $4$ of the periodic table, it will share $4$ electrons and use an oxidation state of $4$ .

$C = 1 (4) = 4$

Step 2

Since $O$ is in column $6$ of the periodic table, it will share $6$ electrons and use an oxidation state of $6$ .

$O = 2 (- 2) = - 4$

Step 3

This is the full list of oxidation states for this molecule.

$C = 4, O = - 4$