Electron configuration
What Electron configuration means in Chemistry A-Level, as defined for OCR.
Definitions of Electron configuration
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Reference: OCR
This fills the lowest available energy sub-shell first, so 4s fills before 3d, giving potassium 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹.
Built by filling subshells in order of increasing energy, respecting the 1s, 2s, 2p, 3s, 3p, 4s, 3d sequence.
Topics that use Electron configuration
- Electron structure (OCR A-Level)
Related terms
- Atomic orbital
- Atomic orbitals
- Cations lose electrons, anions gain electrons
- Distinguishing capacity from filling order
- Electron capacity of s-, p- and d-sub-shells
- Fixed number of orbitals per sub-shell
- Ion electron configurations
- Noble-gas shorthand
Using Electron configuration in the exam
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