Identify the orbital shown below: A) px B) py C) dz² D) pz E) dxz
The Correct Answer and Explanation is:
Correct Answer: D) pz
Explanation
The image shows an orbital that has two lobes aligned along the z-axis, with a node (a region of zero probability) at the nucleus. This is the classic shape of a p-orbital. There are three p-orbitals in a given energy level (starting from n = 2), and they are designated as px, py, and pz depending on their orientation in space.
- The px orbital is aligned along the x-axis.
- The py orbital is aligned along the y-axis.
- The pz orbital, which is the correct answer here, is aligned along the z-axis — as clearly shown in the image.
P-orbitals are dumbbell-shaped, and their orientation is determined by their magnetic quantum number (m_l), which can be -1, 0, or +1. Each p-orbital is orthogonal (perpendicular) to the others, and they represent the probability distribution of an electron in that orientation.
Now, let’s examine why the other options are incorrect:
- A) px: This would show the dumbbell shape aligned along the x-axis, not the z-axis.
- B) py: This orbital would be aligned along the y-axis.
- C) dz²: While this orbital has a unique shape (a donut-shaped ring around a dumbbell), it is not what’s shown here.
- E) dxz: This d-orbital has a four-lobed shape and lies in the xz plane — again, not what’s shown.
In summary, the image displays a simple p-orbital oriented vertically along the z-axis, which makes the correct identification pz. The understanding of orbital orientation is essential in chemistry for predicting molecular bonding, shape, and behavior of atoms in molecules.
