What is the shape of the 2p orbitals?
A) sphere
B) dumbbell
C) cloverleaf
D) raindrop
The correct answer and explanation is:
The correct answer is B) dumbbell.
The shape of the 2p orbitals is often described as a “dumbbell” because of their appearance. These orbitals have a characteristic shape where there are two lobes, one on each side of the nucleus, with a node at the center. This node represents a region where the probability of finding an electron is zero.
The 2p orbitals are part of the second energy level in an atom. The “2” indicates the principal energy level, while the “p” denotes the type of orbital. The “p” orbitals are distinct from the “s” orbitals, which have spherical shapes. The key difference lies in how the electrons are distributed in space around the nucleus.
In an atom, there are three 2p orbitals, each oriented differently in space, corresponding to the three possible values of the magnetic quantum number (mₗ): -1, 0, and +1. These three orbitals are usually denoted as 2pₓ, 2pᵧ, and 2p𝓏. They are oriented along the x, y, and z axes, respectively. Each orbital has the same dumbbell shape, but they point in different directions.
This dumbbell shape is a result of the angular part of the wavefunction that describes the electron’s probability distribution. Unlike the spherical “s” orbitals, where the electron is equally likely to be found in all directions from the nucleus, the p orbitals have regions of higher electron density in two lobes. This shape plays a significant role in bonding and chemical reactions, especially in covalent bonds, where the overlap of p orbitals forms a bond between atoms.
To summarize, the shape of 2p orbitals is best described as a “dumbbell,” reflecting the two lobes that characterize their electron probability distribution.