Difference WikiChemistry

Difference Between Electron Geometry and Molecular Geometry

Main Difference

The main difference between Electron Geometry and Molecular Geometry is that the Electron Geometry includes both the bonds and electron pairs in the molecule, whereas the Molecular Geometry includes only the number of bonds that are present in a molecule.

Electron Geometry vs. Molecular Geometry

Electron geometry is formed by both the electron pairs and bonds present in a molecule; on the other hand, molecular geometry is formed by only bonds that are present in a molecule. Electron geometry contains electron pairs; on the flip side, molecular geometry does not contain electron pairs. In electron geometry, lone pairs are also counted; on the opposite side, in molecular geometry, lone pairs are not counted.

ADVERTISEMENT

In electron geometry, the total number of pair of electrons are considered; on the other side of the coin, in molecular geometry, the total number of electron pairs that are participated in bonding is considered. Electron geometry gives us information about the organization of groups of electrons; on the other hand, molecular geometry gives us information about the organization of only atoms in molecule except for lone pairs.

Electron geometry can be determined by the help of the VESPR Theory; on the flip side, molecular geometry is defined by the arrangement of atoms around the nuclei of the central atom. Electron geometry includes both bonding and non-bonding electron pairs; on the other side of the coin, molecular geometry includes only the bonding electron pairs.

ADVERTISEMENT

Comparison Chart

Electron GeometryMolecular Geometry
Electron geometry is the geometry that determines the shape of the molecule including both the electron pairs and bonds in the moleculeMolecular geometry is the geometry that determines the shape of the molecule including only the bonds in the molecule
Electron Pairs
Electron geometry includes electron pairsMolecular geometry does not include electron pairs
Bonding Electron Pairs
Electron geometry includes both bonding electron pairs and non-bonding electron pairsMolecular geometry includes only bonding electron pairs
Helpful
Electron geometry is useful in giving the arrangement of the electron groupsMolecular geometry is useful in giving the arrangement of the atoms in a molecule
Determination
Electron geometry can also be determined by VESPR TheoryMolecular geometry can also be determined by the arrangement of the atoms around the nuclei of the central atom
ADVERTISEMENT

What is Electron Geometry?

Electron geometry is the type of geometry that is useful in giving the shape of the molecule that includes both electron pairs and bond pairs that are present in a molecule. It can also be determined by the help of the VSEPR Theory. The main purpose of the electron geometry is to find out the geometry of the molecule by the arrangement of atoms and electrons around the central atom. Electron pairs are considered only in the electron geometry and neglected in the molecular geometry.

It gives us the arrangement of groups of electrons around the central atom. Electron geometry can also be determined by decreasing the repulsions between the lone pair of electrons. In electron geometry, it also considers the region of electrons having different densities. Non-bonding electrons are also known as the lone pair of electrons. That’s why the electron geometry depends upon the number of these electron regions. By decreasing the repulsion between these electronic regions, electron geometry gives us the shape of the molecules.

An example of electron geometry can be given by using the formula of methane. The central atom is carbon, and the number of valence electrons is 4. The four valence electrons are denoted by the hydrogen atom to complete the valence shell of both carbon and hydrogen atoms by the sharing process. There are four single bonds in the structure of the molecule. Therefore, it is summarized that the geometry of methane is tetrahedral.

What is Molecular Geometry?

Molecular geometry is the type of geometry that is useful in giving the shape of the molecule that includes only the bond pair of electrons that are present in a molecule. It is measured by the arrangement of atoms around the nuclei of the central atom. Its main purpose is to find out the geometry of the molecule by the arrangement of atoms in a molecule. In molecular geometry, electron pairs are mainly not considered. It gives us the position of the atoms in the structure of the molecule.

The repulsion between the bonded atoms also considered being less to find out the main purpose of the geometry. The main difference between the electron geometry and molecular geometry is that when we discuss the shape of the molecule, it means we are determining the molecular geometry; on the other hand, when we discuss the geometry of electron pairs, it means we are determining the electron geometry.

As molecular geometry is used to determine the shape of the molecule, so we must use the lewis structure when we are discussing the shape of molecules in the molecular geometry by drawing it in the form of a lewis method to determine the number of bonding electrons. The example of molecular geometry is the water molecule. It contains two bonding electrons and two non-bonding electrons. The central atom is the oxygen molecule having two lone pairs. It receives two bonding electrons from the hydrogen atom by the sharing method. So, the molecular geometry of the water molecule is bent.

Key Differences

  1. Electron geometry determines the shape of the molecule that involves the electron pair and bond pair; on the other hand, molecular geometry determines the shape of the molecule that involves only the bond pairs.
  2. Electron geometry considers electron pair; on the flip side, molecular geometry does not consider the electron pair.
  3. Electron geometry helps give the arrangement of electron pairs; on the opposite side, molecular geometry helps give the arrangement of atoms around the central nuclei.
  4. Electron geometry includes both bonding and non-bonding electrons; on the other side of the coin, molecular geometry includes only bonding electrons.
  5. Electron geometry can also be determined by the VESPR Theory; on the other hand, and molecular geometry can also be determined by the arrangement of atoms around the nuclei of the central atom.
  6. In electron geometry, the total number of electron pairs and bond pairs are counted; on the flip side, in molecular geometry, the total number of bond pairs is counted.

Conclusion

The above discussion concludes that both electron geometry and molecular geometry is the geometry that is used for the determination of the shape of the molecule. Electron geometry gives us the shape of the molecule that includes both bonding and non-bonding electron pairs; on the other hand, molecular geometry gives us the shape of the molecule that includes only the bonding electron pairs.

Harlon Moss

Harlon currently works as a quality moderator and content writer for Difference Wiki. He graduated from the University of California in 2010 with a degree in Computer Science. Follow him on Twitter @HarlonMoss