Molecular Orbital Theory
Chapter Name : Chemical Bonding And Molecular Structure |
Sub Topic Code : 102_11_04_08_02 |
Topic Name : Molecular Orbital Theory |
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Sub Topic Name : Linear Combination Of Atomic Orbitals |
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Introduction
• According to wave mechanics, the atomic orbitals can be expressed by wave functions (?) which represents the amplitude of the electron waves. • The formation of molecular orbitals can be understood in terms of the constructive or destructive interference of the electron waves of the combining atoms. • The formation of molecular orbitals may be described by the linear combination of atomic orbitals that can take place by addition and subtraction of wave functions of individual atomic orbitals, giving rise to bonding and antibonding molecular orbitals.
Pre-Requisites:
Covalent bond, polyatomic molecule , orbital
Activity:
Waves on a beach, dripping water forming patterns over a bucket of water.
Real Life Question:
Why do huge waves form in the sea? How do raindrops form patterns over a puddle of water?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Molecular orbital | Orbitals formed when atomic orbitals combine by hybridisation. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Water bowl, dripping tap | Observe how the water dripping from a tap forms concentric patterns over the water in the bowl. If another dripping source is placed nearby, see how the pattern changes. |
Real life uses :
Constructive interference is used to amplify sound waves and destructive interference is used to lower the amplitude of sound waves.
Places to visit :
Zoo, garden, gym, bathroom.
Practical examples around us
| Examples | Explainations |
|---|---|
| Concentric ring patterns over the water from raindrops | Concentric rings forms due to waves which are formed when the water is disturbed from the drops. If another drop falls nearby the pattern is disturbed due to destructive interference. |
What you learn in Theory:
Molecular orbital forms due to constructive and destructive interference giving rise to bonding and antibonding molecular orbitals.
What you learn in Practice:
Constructive and destructive interference takes place due to addition or subtraction of wave functions.