Question

Which of the following pairs of d-orbitals will have electron density along the axes?

• A. $d_{z^2} , d_{xz}$
• B. $d_{xz} , d_{yz}$
• C. $d_{z^2} , d_{x^2 - y^2}$
• D. $d_{xy} , d_{x^2 - y^2}$

Answer 1

The Correct Option is C

To determine which pairs of d-orbitals have electron density along the axes, we need to understand the orientation of each d-orbital in space. The five d-orbitals are:

1. d_{xy}
2. d_{yz}
3. d_{xz}
4. d_{x^2 - y^2}
5. d_{z^2}

The d_{x^2 - y^2} and d_{z^2} orbitals orient along the Cartesian axes:

• d_{x^2 - y^2}: The lobes of this orbital are directed along the x- and y-axes.
• d_{z^2}: The electron density is concentrated along the z-axis, featuring a distinct doughnut-shaped region of electron density in the x-y plane.

On the other hand, the remaining orbitals:

• d_{xy}: Lies in the xy-plane, with the lobes between the axes.
• d_{yz}: Lies in the yz-plane, with the lobes between the axes.
• d_{xz}: Lies in the xz-plane, with the lobes between the axes.

Therefore, only the d_{x^2 - y^2} and d_{z^2} orbitals feature electron density directly along the axes.

The correct answer is: d_{z^2} , d_{x^2 - y^2}