Theories of Chemical Bonding (VBT & MOT)

The atomic orbitals having unpaired electrons undergo overlapping to produce covalent bond, This is according to

• VSEPR Theory
• Valence Bond Theory
• Molecular Orbital Theory
• Lewis Theory

All atomic orbitals of valance shell undergoes overlapping to produce molecular orbitals. This is according to:

• VSEPR Theory
• Molecular Orbital Theory
• Valence Bond Theory
• Lewis Structure Theory

Bonding molecular orbitals are formed by:

• constructive overlap of atomic orbitals

• Breaking of atomic orbitals
• destructive overlap of atomic orbitals

• Combination of atomic nuclei

VBT is not able to explain:

• The valency of Be, B & C

• The paramagnetic behavior of O2

• The color of transition metal complexes
• All of these

sigma bonds are stronger than pi bonds because

• Sigma bonds involve end-to-end overlapping and Pi bonds involve side-to-side overlapping
• Pi bonds are double bonds and Sigma bonds are single bonds
• Sigma bonds are formed by the overlap of s-orbitals and Pi bonds are formed by the overlap of p-orbitals
• Pi bonds are weaker because they are formed by the overlap of d-orbitals

Sigma p-p overlapping is more stronger than sigma s-s overlapping because:

• p orbitals are more diffuse than s orbitals
• p orbitals have higher energy than s orbitals
• p orbitals are more directional than s orbitals
• p orbitals have more nodes than s orbitals

The electron density is zero at:

• The nucleus of an atom
• The center of a molecule
• The nodes of an atomic orbital
• The outermost shell of an atom

Atomic orbital is influenced by one nucleus and molecular orbital is by two or more nuclei. therefore, molecular orbitals are :

• Less stable than atomic orbital

• are polycentric & more stable than atomic orbitals

• Equal in stability to atomic orbitals
• monocentric & stable

The bond order of Nitrogen molecule is:

• 1
• 2
• 3
• 4

The magnetic behavior of oxygen molecule is:

• Diamagnetic
• Paramagnetic
• Ferromagnetic
• Antiferromagnetic