To draw the Lewis dot structure for carbon dioxide (CO2), start by determining the total number of valence electrons. Carbon has 4 valence electrons, and each oxygen has 6, giving us a total of 16 valence electrons.
Next, place the carbon atom in the center, as it is less electronegative than oxygen. Connect the carbon to the two oxygen atoms with single bonds. Since you have used 4 valence electrons for the bonds, that leaves you with 12 electrons to distribute.
Place 6 electrons (or 3 pairs) on each oxygen atom to satisfy their octet. To ensure that the carbon also has an octet, you can convert a lone pair from each oxygen into a double bond with carbon, resulting in the structure:
O=C=O
In this structure, carbon has 4 bonding electrons (from the two double bonds) and no lone pairs, while each oxygen atom has 4 non-bonding electrons (2 lone pairs) and 4 bonding electrons (from the double bond).
Now, let’s discuss the electron geometry and molecular shape. The electron geometry is determined by the number of regions of electron density around the central atom (carbon). In this case, there are two double bonds around carbon, which means there are two regions of electron density. This results in a linear electron geometry.
The molecular shape is also linear, as it is determined by the arrangement of the atoms in the molecule. Therefore, we can conclude:
- Electron Geometry: Linear
- Molecular Shape: Linear
Finally, to determine if CO2 is polar or nonpolar, we analyze the molecular geometry. Although the individual C=O bonds are polar due to the difference in electronegativity between carbon and oxygen, the linear shape means that the bond dipoles cancel each other out, rendering the molecule nonpolar.
In summary, the Lewis dot structure for CO2 is O=C=O, the electron geometry is linear, the molecular shape is also linear, and CO2 is a nonpolar molecule.