Sublevel: definition in chemistry
Sublevel: A subdivision of an electron energy level (shell), labeled s, p, d or f. These sublevels hold at most 2, 6, 10 and 14 electrons.
Each sublevel is made of orbitals: s has one, p has three, d has five and f has seven, and each orbital holds up to two electrons. The first shell has only an s sublevel, the second has s and p, the third has s, p and d, and the fourth adds f. Electron configurations such as 1s² 2s² 2p⁶ list how many electrons are in each sublevel.
Examples
- 1s — the only sublevel in the first shell, holding up to 2 electrons
- 2p — three orbitals holding up to 6 electrons
- 3d — filled across the first row of transition metals
- Oxygen's configuration: 1s² 2s² 2p⁴
On the periodic table
The table is divided into s, p, d and f blocks according to the sublevel that each element's highest-energy electrons are filling.