Question

study the following sketch of a molecular orbital (mo) in a homonuclear diatomic molecule. this mo was formed by combining one 2s 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 2s orbital on one of the separate atoms?

Explanation:

Step1: Identify MO symbol

When two 2s atomic - orbitals combine, the antibonding molecular orbital is denoted as $\sigma_{2s}^*$.

Step2: Determine bonding type

In the sketch, there is a node between the two nuclei. Antibonding molecular orbitals have nodes between the nuclei, so it is antibonding.

Step3: Compare energy

Antibonding molecular orbitals have higher energy than the atomic orbitals from which they are formed. So the energy of this $\sigma_{2s}^*$ MO is higher than the energy of a 2s orbital on one of the separate atoms.

Answer:

Question	Answer
Is this a bonding or antibonding MO?	antibonding
What is the energy of this MO, compared to the energy of a 2s orbital on one of the separate atoms?	higher