Linear Structures

A linear structure refers to a molecule where all atoms are arranged in a straight line. In this case, the correct answer is option B, CO2 (carbon dioxide). Let's explore why CO2 is a linear molecule.

Explanation

- Carbon dioxide (CO2) consists of two oxygen atoms bonded to a central carbon atom.
- The Lewis structure for CO2 shows that the carbon atom and both oxygen atoms are connected by double bonds.
- The carbon atom is in the center of the molecule, surrounded by the two oxygen atoms.
- Each oxygen atom has two lone pairs of electrons, while the carbon atom has no lone pairs.
- The shape of a molecule is determined by the arrangement of its atoms and lone pairs.
- In the case of CO2, the molecule is linear because the carbon atom and both oxygen atoms are in a straight line.
- Since there are no lone pairs on the central carbon atom, there are no repulsive forces to distort the linear shape.
- The linear structure of CO2 can also be understood using the VSEPR (Valence Shell Electron Pair Repulsion) theory.
- According to VSEPR, the electron pairs surrounding the central atom repel each other and try to position themselves as far apart as possible.
- In the case of CO2, the two oxygen atoms are positioned on opposite sides of the carbon atom, maximizing the distance between them and resulting in a linear shape.

Conclusion

In summary, among the given options, CO2 (carbon dioxide) is the linear molecule. The linear shape of CO2 arises due to the absence of lone pairs on the central carbon atom and the repulsion between the electron pairs surrounding it.