Bonding molecular orbital

Definition

A bonding molecular orbital is a region in a molecule where the probability of finding electrons is high, formed by the constructive interference of atomic orbitals from two or more atoms. This type of orbital allows for the attraction between nuclei, stabilizing the molecule. The formation of bonding molecular orbitals is essential for understanding how atoms combine to create stable molecules, influencing properties like bond length and strength.

5 Must Know Facts For Your Next Test

1. Bonding molecular orbitals are lower in energy than the atomic orbitals from which they are formed, contributing to molecule stability.
2. Electrons in bonding molecular orbitals help hold the atoms together through electrostatic attractions between positively charged nuclei and negatively charged electrons.
3. When two atomic orbitals combine to form a bonding molecular orbital, there is an increase in electron density between the nuclei, which strengthens the bond.
4. The number of bonding molecular orbitals formed equals the number of atomic orbitals combined, following the principle of conservation of orbitals.
5. Bonding molecular orbitals can accommodate up to two electrons with opposite spins, following the Pauli exclusion principle.

Review Questions

• How does the formation of bonding molecular orbitals contribute to the stability of a molecule?
  • The formation of bonding molecular orbitals contributes to molecule stability by lowering the overall energy of the system. When atomic orbitals combine constructively, they create a region of higher electron density between the nuclei, which enhances attraction and minimizes repulsion. This increased electron density in bonding regions leads to stronger interactions that hold atoms together, making the resulting molecule more stable compared to when atoms are isolated.
• Compare and contrast bonding and antibonding molecular orbitals in terms of their energy levels and contributions to molecular stability.
  • Bonding molecular orbitals are lower in energy than the atomic orbitals from which they are derived, contributing positively to molecular stability by promoting attraction between nuclei. In contrast, antibonding molecular orbitals are higher in energy and often have nodes between nuclei, leading to repulsion and decreased stability when populated with electrons. While bonding orbitals stabilize a molecule by attracting electrons towards the bond axis, antibonding orbitals can destabilize it if occupied, highlighting their crucial roles in determining a molecule's overall stability.
• Evaluate how the concept of hybridization relates to the formation of bonding molecular orbitals in multi-atom systems.
  • Hybridization plays a vital role in forming bonding molecular orbitals by allowing atomic orbitals from different atoms to mix and create new hybrid orbitals tailored for bonding. This process facilitates various geometrical arrangements, such as tetrahedral or trigonal planar configurations, which affect how atomic interactions manifest as bonding. By enabling atoms to form stronger bonds through effective overlap in their respective hybridized states, hybridization enhances the creation of stable bonding molecular orbitals and ultimately influences molecular properties like shape and reactivity.

Related terms

atomic orbital: A mathematical function that describes the wave-like behavior of electrons in an atom, providing information about the probable location of an electron.

antibonding molecular orbital:

A type of molecular orbital that results from the destructive interference of atomic orbitals, characterized by a node between the nuclei and leading to decreased stability.

hybridization: The concept of mixing atomic orbitals to create new hybrid orbitals, which can explain the geometry and bonding properties of molecules.