Answer:
O=C=O.
Four nonbonding electron pairs.
Step-by-step explanation:
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In this case, as you can see on the attached picture, there are two double bonds between the central carbon atom and those two oxygen atoms because each oxygen shares two electrons to the central carbon for them to attain the octet. Moreover, the enclosed dots represent the nonbonding electron pairs, which are four in total. It is importante to notice that carbon dioxide (O=C=O) has a complete octet whereas carbon monoxide (C=O) does has an incomplete octet for C.
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