1. What are valence electrons or valency of an atom?

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The electrons present in outermost orbit of an atom determine the valency of atom and hence called valency electrons. In chemistry, valence electrons are the electrons in the outside or valence electron shell of an atom.

2. What are Atomic Orbitals? According to Molecular Orbital Theory, the shape and size of a molecular orbital depends upon what?

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a) Atomic orbitals are mathematical functions that provide insight into the wave nature of electrons (or pairs of electrons) that exist around the nuclei of atoms.
b) The shape and size of a molecular orbital depend upon the shape, size, number and orientation of the combining atomic orbitals.

3. What are Atomic Orbitals?

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Atomic orbitals are mathematical functions that provide insight into the wave nature of electrons (or pairs of electrons) that exist around the nuclei of atoms.

4. Names of Atomic Orbitals and the Relationship between the Different Quantum Numbers that describe them?

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• The s orbital, where the value of the azimuthal quantum number is equal to 0.
• The p orbital, where the value of the azimuthal quantum number is equal to 1.
• The d orbital, where the value of the azimuthal quantum number is equal to 2.
• The f orbital, where the value of the azimuthal quantum number is equal to 3.
• The g orbital, where the value of the azimuthal quantum number is equal to 4.
• The h orbital, where the value of the azimuthal quantum number is equal to 5.

5. Difference between Bonding Molecular Orbitals and Antibonding Molecular Orbitals?

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6.Which are antibonding orbitals?

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Consider a film of non-uniform thickness as shown in Fig. It is bound by two surfaces OX and OX′ inclined at an angle θ. The thickness of the film gradually increases from O to X. Such a film of non-uniform thickness is known as wedge shaped film.

7. What is molecular orbital theory?

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• The Molecular Orbital Theory (often abbreviated to MOT) is a theory on chemical bonding developed at the beginning of the twentieth century to describe the structure and properties of different molecules.
• The valence-bond theory failed to adequately explain how certain molecules contain two or more equivalent bonds whose bond orders lie between that of a single bond and that of a double bond, such as the bonds in resonance-stabilized molecules.
• This is where the molecular orbital theory proved to be more powerful than the valence-bond theory.
• One of the main impacts of the molecular orbital theory after its formulation is that it paved a new way to understand the process of bonding.
• With this theory, the molecular orbitals are basically considered as linear combinations of atomic orbitals.
• The approximations are further done using the Hartree–Fock (HF) or the density functional theory (DFT) models to the Schrödinger equation.

8. What is the molecular orbital electronic configuration of HF molecule?

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HF molecule has 10 electrons and its electronic configuration is 1s² 2s² σ_spx² [2_py² 2_pz²] σ_spx *.

9. What is the interaction between a pair of orbitals of the same type called?

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The interaction between pair of orbitals of the same type is repulsive like between σ_2s and σ_2p orbitals.