Question

. which of the following​

Answer 1

Answer:

d) Zn²

Explanation:

In the presence of ligands, the originally degenerate 3d orbitals are being split into two different energy levels. The energy difference happens to fall within the energy corresponding to the visible light spectrum.

When white light is shone on a solution containing the transition metal ion, an electron in the low energy level orbital will absorb a photon corresponding to the energy difference and be promoted to the high energy orbital. This promotion of electron from a low energy d orbital to a high energy d orbital is termed "d-d transition".

The rest of the light passes through the solution and what is observed will essentially be white light minus the colour corresponding to the energy that was absorbed. Eg. If the colour blue was absorbed, the solution would appear orange.

As such, there are two conditions that must be fulfilled before we can obtain colour through a d-d transition.

1. There must be at least one electron present in the low energy d orbital to be promoted to the high energy d orbital.
2. There must be a vacancy in the high energy d orbital for the promotion to take place.

Now, let us turn our attention to Zn in solution. Zn forms only Zn2+ as a stable ion in aqueous solution. Zn2+ has the electronic configuration of 1s2 2s2 2p6 3s2 3p6 3d10

In the presence of water ligands, the 3d orbitals will be split into two different energy levels.