Question

what is the correct electron dot formula for carbon dioxide?
○ :o::c::o:
○ :o:c:o:
○ :o::c::o:
○ :c::o:::o:

Explanation:

Step1: Determine valence electrons

Carbon has 4 valence electrons and oxygen has 6 valence electrons. In $\ce{CO2}$, total valence electrons = $4+(2\times6)=16$.

Step2: Arrange atoms

Carbon is the central atom with oxygen atoms on either side.

Step3: Form bonds and distribute electrons

Carbon forms double bonds with each oxygen atom to satisfy the octet rule. Each oxygen has 2 lone pairs of electrons after forming the double bond with carbon. So the electron - dot structure is $\ce{:O::C::O:}$.

Answer:

The correct electron - dot formula for carbon dioxide is $\ce{O::C::O}$. So the answer is the first option $\ce{:O::C::O:}$ (assuming the first option is the one with two double bonds between carbon and oxygen and appropriate lone - pair electrons on oxygen atoms).