Electron Configurations, Subshells and Orbitals

Electron Configuration: The way in which electrons are organised in Energy Levels (ELs) of an atom

Ex. Chlorine: 2-8-7

Subshells: The subsidiary levels into which each energy level is split

Ex. Chlorine: 1s²2s²2p^6 3s²3p^5

Orbitals: Pairs of electrons within sublevels

Energy Levels - Capacities

EL 1: 2 e-

EL 2: 8 e-

EL 3: 18 e-

EL 4: 32 e-

Sublevels - Type + Capacity

“s” (sharp): 2e-, 1 orbital

“p” (principal): 6e-, 3 orbitals

“d” (diffuse): 10e-, 5 orbitals

“f” (fundamental): 14e-, 7 orbitals

s Sublevel is always filled first

Box Diagram - Diagram to represent orbitals

Ex. SL 3p in Chlorine [⬆⬇] [⬆⬇] [⬆]

Always fill all orbitals with an arrow pointing up before doing the arrows pointing down in order