study the following sketch of a molecular orbital (mo) in a homonuclear diatomic molecule. this mo was…
study the following sketch of a molecular orbital (mo) in a homonuclear diatomic molecule. this mo was formed by combining one 1s atomic orbital from each atom. the dark dots in this sketch are the nuclei. now use the sketch to complete the table below. write the symbol for this mo. is this a bonding or antibonding mo? what is the energy of this mo, compared to the energy of a 1s orbital on one of the separate atoms?
Answer
Explanation:
Step1: Identify the orbital type
When two 1s atomic orbitals combine head - on, they form a $\sigma$ orbital. The given sketch shows a symmetric orbital about the internuclear axis, which is characteristic of a $\sigma$ orbital.
Step2: Determine bonding or antibonding
In a bonding molecular orbital, the electron density is concentrated between the two nuclei. The sketch shows significant electron density between the nuclei, so it is a bonding MO.
Step3: Compare energy
Bonding molecular orbitals have lower energy than the atomic orbitals from which they are formed. When 1s atomic orbitals combine to form a bonding $\sigma$ orbital, the energy of the $\sigma$ orbital is lower than the energy of the 1s orbital on a separate atom.
Answer:
| Question | Answer |
|---|---|
| Write the symbol for this MO. | $\sigma$ |
| Is this a bonding or antibonding MO? | bonding |
| What is the energy of this MO, compared to the energy of a 1s orbital on one of the separate atoms? | lower |