Question
Chemistry Question on Chemical bonding and molecular structure
Identify the correct increasing order of energies of molecular orbitals for F2 molecule.
A
σ1s<σ1s∗<σ2s<σ2s∗
B
σ1s<σ2s<σ1s∗<σ2s∗
C
σ1s<σ1s∗<σ2s∗<σ2s
D
σ1s∗<σ1s<σ2s∗<σ2s
Answer
σ1s∗<σ1s<σ2s∗<σ2s
Explanation
Solution
Let's break down the options to understand why this is the correct order:
- In the F2 molecule, the σ1s bonding orbital is formed by the overlap of the two 1s atomic orbitals from each fluorine atom. This bonding orbital is lower in energy compared to the other molecular orbitals.
- The σ1s∗ antibonding orbital is formed by the destructive overlap of the two 1s atomic orbitals. It is higher in energy than the σ1s bonding orbital.
- The σ2s bonding orbital is formed by the overlap of the two 2s atomic orbitals from each fluorine atom. It is lower in energy than the σ* 1s orbital.
- Finally, the σ2s∗ antibonding orbital is formed by the destructive overlap of the two 2s atomic orbitals. It is higher in energy than the σ2s bonding orbital.
Therefore, the correct order is σ1s∗<σ1s<σ2s∗<σ2s, which corresponds to option (D).