Each type of atomic orbital subshell (s, p, d, f) has a specific maximum capacity for electrons. While every individual orbital can hold a maximum of two electrons, the s, p, d, and f designations refer to subshell types that contain varying numbers of these individual orbitals, leading to different total electron capacities.
Maximum Electron Capacity in SPDF Orbital Subshells
Here's a breakdown of the maximum number of electrons for each subshell type:
- s orbital (subshell): Can contain up to two (2) electrons.
- p orbital (subshell): Can contain up to six (6) electrons.
- d orbital (subshell): Can contain up to ten (10) electrons.
- f orbital (subshell): Can contain up to fourteen (14) electrons.
Understanding Atomic Orbitals and Electron Capacity
Atomic orbitals describe the probable location and wave-like behavior of an electron in an atom. These are grouped into subshells, which are further categorized by their shape and energy level, denoted by the letters s, p, d, and f.
The Pauli Exclusion Principle
A fundamental rule governing electron configuration is the Pauli Exclusion Principle. It states that no two electrons in an atom can have the exact same set of four quantum numbers. Practically, this means that each individual orbital—regardless of whether it's an s, p, d, or f type—can hold a maximum of two electrons, provided they have opposite spins.
Electron Capacity by Subshell Type
The different capacities for s, p, d, and f subshells arise because each subshell type contains a specific number of individual orbitals:
- s Subshell:
- Contains one individual s orbital.
- Therefore, it can hold 1 orbital * 2 electrons/orbital = 2 electrons.
- Example: The 1s orbital in hydrogen or helium.
- p Subshell:
- Contains three individual p orbitals (e.g., pₓ, pᵧ, p₂).
- Therefore, it can hold 3 orbitals * 2 electrons/orbital = 6 electrons.
- Example: The 2p subshell in oxygen, which has 4 electrons in its 2p orbitals.
- d Subshell:
- Contains five individual d orbitals.
- Therefore, it can hold 5 orbitals * 2 electrons/orbital = 10 electrons.
- Example: The 3d subshell in transition metals like iron.
- f Subshell:
- Contains seven individual f orbitals.
- Therefore, it can hold 7 orbitals * 2 electrons/orbital = 14 electrons.
- Example: The 4f subshell in lanthanides.
The following table summarizes the electron capacities for each subshell type:
| Subshell Type | Number of Individual Orbitals | Maximum Electrons |
|---|---|---|
| s | 1 | 2 |
| p | 3 | 6 |
| d | 5 | 10 |
| f | 7 | 14 |
This understanding is crucial for predicting electron configurations and chemical behavior, as it dictates how electrons fill energy levels within atoms. For more details on atomic orbitals and electron configurations, you can refer to resources like Khan Academy or Chemistry LibreTexts.
