Chemical Bonding Demystified: The Kossel-Lewis Approach
by Yuvi K - December 16, 2023
Chemical Bonding Demystified: The Kossel-Lewis Approach
Chemical bonding is an essential part of chemistry. This is the process in which electrons from one atom are shared by another atom, forming a bond between the two. This bond allows them to interact and form molecules and compounds with unique properties. But how does this process actually occur? Let’s find out!
In 1916, German physicists Walther Kossel and Gilbert N. Lewis proposed the Kossel-Lewis approach to explaining chemical bonding. According to their theory, it is the electrostatic forces of attraction between protons and electrons that cause bonding. When electrons are shared between two atoms, it creates an electrostatic attraction called the “bonding force.” The bonding force is stronger than the repulsive forces that result from the protons from both atoms. This electrostatic attraction creates a stronger bond than the individual atoms have alone.
Structures of Atomic Orbitals
The Kossel-Lewis approach also explains the different shapes and properties of molecules and compounds. To understand this, you need to know how electrons are arranged in atoms. Electrons are arranged in “atomic orbitals” – regions of space around an atom in which electrons are found with certain probabilities.
Each type of atom has its own unique set of atomic orbitals, and the arrangement of electrons in these orbitals determines the shape and properties of the molecules and compounds that form from them. The most common type of orbital is the “s” orbital, which is a sphere-like region of space around the atom.
Hybridization
The Kossel-Lewis approach also explains “hybridization” – the process of combining two or more atomic orbitals to create new hybrid orbitals. When the electrons in different atomic orbitals overlap, they create a new hybrid orbital with a different shape and properties than the original orbitals.
For example, when two “s” orbitals overlap, they create a “sp” orbital. The “sp” orbital has a shape that is intermediate between the two original orbitals, and the electrons in the “sp” orbital are arranged in a way that is different from the “s” orbitals. This type of hybridization is often seen in compounds that form single, double, and triple bonds.
Bond Length and Bond Angle
The Kossel-Lewis approach also explains the lengths and angles of chemical bonds. The bond length is the distance between the nuclei of two bonded atoms. The bond angle is the angle formed between the bonds connecting two atoms. The bond length and angle are determined by the overlapping orbitals, and the type of hybrid orbitals created. For example, the bond length and angle of a single bond is shorter and smaller than the bond length and angle of a double or triple bond.
Valence Shell Electron Pair Repulsion (VSEPR) Model
Finally, the Kossel-Lewis approach explains the VSEPR Model. This is a model that explains the arrangement of atoms and electrons in a molecule. According to this model, the arrangement of atoms and electrons in a molecule is determined by the repulsive forces between electron pairs. When two electron pairs repel each other, the atoms will spread apart, creating the three-dimensional shape of the molecule.
Conclusion
The Kossel-Lewis approach is a valuable tool for understanding chemical bonding. It explains the electrostatic forces between electrons and protons that cause bonding, the structures of atomic orbitals, hybridization, bond lengths and angles, and the VSEPR Model. By understanding the Kossel-Lewis approach, chemists have a better understanding of the processes that create molecules and compounds.
