Sublevel — Science definition
A subdivision of an energy level, labeled s, p, d, or f, each with a characteristic shape and capacity.
Where it is taught
- Electron Configuration — Atoms, Electrons & Periodicity, Physical Science: Chemistry, Grade 11
In use
For a one-electron atom, shell energy depends on n; in many-electron atoms, sublevel energies also depend on interactions and shielding.
Electron Configuration
Questions using sublevel
Problem 1
Which sublevel can hold a maximum of 10 electrons?
- f
- s
- p
- d
Answer and explanation
d
The d sublevel has 5 orbitals × 2 electrons = 10 electrons.
Problem 2
Explain why the 4 s sublevel is filled before 3d even though 3d has a lower principal quantum number.
Answer and explanation
Electrons fill in order of increasing energy, not simply increasing n. The 4 s sublevel happens to be slightly lower in energy than 3d, so by the Aufbau principle electrons occupy 4 s first.
Problem 3
How many orbitals are in a p sublevel?
- 3
- 5
- 7
- 1
Answer and explanation
3
A p sublevel has 3 orbitals, holding up to 3 × 2 = 6 electrons.
Taught alongside
- energy level (n)
- orbital
- electron configuration
- Aufbau principle
- Pauli exclusion principle
- Hund's rule
- valence electrons