Subshell
Definition and meaning of Subshell in chemistry.
A subshell is a specific region within an atom where electrons live. It acts as a smaller subdivision of a main electron shell. Each subshell has a unique shape and holds a set number of electrons.
In more detail
Atoms are built with layers of electrons called principal shells. You can think of these main shells like the floors of a parking garage. Inside each floor, there are different parking sections with specific shapes.
These sections are the subshells. We label these subshells with the letters s, p, d, and f. The letters describe the physical shape of the electron clouds.
An s subshell looks like a hollow sphere. A p subshell looks like a pinched dumbbell. The d and f subshells have much more complex flower shapes.
Each shape determines how atoms can bond with one another. We find the number of a subshell using the azimuthal quantum number. This mathematical rule dictates exactly how many subshells fit on each main level.
A common student mistake is confusing a subshell with an orbital. A subshell is a collection of orbitals that share the same energy level and shape. Each individual orbital inside the subshell can only hold two electrons.
The total capacity of a subshell depends on its shape. An s subshell holds two electrons. A p subshell holds six electrons.
A d subshell holds ten electrons. An f subshell holds fourteen electrons.
Key facts
| Field | General Chemistry |
|---|---|
| Subshell Types | s, p, d, and f |
| Organization | Subdivisions of a principal electron shell |
| Component Parts | Made up of individual atomic orbitals |
| Maximum Capacity | s holds 2, p holds 6, d holds 10, f holds 14 |
| Shape Rule | Dictated by the azimuthal quantum number |
The second main electron shell contains both a 2s and a 2p subshell. The 2s subshell is a single spherical room that holds two electrons. The 2p subshell contains three separate dumbbell shaped orbitals. Since each orbital holds two electrons, the entire 2p subshell can hold up to six electrons. Together, this entire second floor holds eight total electrons.
Frequently asked questions
What is the difference between a shell, a subshell, and an orbital?
A shell is the main energy level. A subshell is a specific shaped region within that level. An orbital is an exact slot in the subshell holding two electrons.
Why do subshells have letter names like s, p, d, and f?
The letters come from old terms used to describe light spectra. They stand for sharp, principal, diffuse, and fundamental.
In what order do electrons fill subshells?
Electrons fill the lowest energy subshells first. They typically start with 1s, then 2s, 2p, 3s, 3p, 4s, and then 3d.