Question

how many total valence electrons are present in a molecule of carbon dioxide (co₂)?
18
16
8
12
which of the following lewis structures for carbon dioxide (co₂) is the most likely?
o - c - o
o = c - o
o = c = o
o - c = o

Explanation:

Step1: Determine valence electrons of C and O

Carbon (C) has 4 valence electrons and oxygen (O) has 6 valence electrons. In $CO_2$, there is 1 C and 2 O atoms.

Step2: Calculate total valence electrons

The total number of valence electrons is $4+(2\times6)=4 + 12=16$. But this is wrong in the context of the multiple - choice. Let's re - calculate:
Carbon has 4 valence electrons and each oxygen has 6 valence electrons. So for $CO_2$, the total number of valence electrons is $4+(6\times2)=16$.
The Lewis structure of $CO_2$ has a central carbon atom double - bonded to two oxygen atoms ($O = C=O$). Each double bond consists of 4 electrons.

For the first question:
The total number of valence electrons in $CO_2$ is 16. But since it's not in the options, let's analyze the correct way of counting. Carbon has 4 valence electrons and each oxygen has 6. So $4+6 + 6=16$.
For the second question:
The Lewis structure of carbon dioxide is $O = C=O$.

Answer:

For the first question: None of the options are correct.
For the second question: O=C=O (assuming the option with double bonds is the one represented as O=C=O among the given choices which are not clearly formatted here but this is the correct Lewis structure).