ORBITAL NOTATION

1
ORBITAL NOTATION
FILLING ORDER memorize! 1s_ 2s_ 2p_ _ _ 3s_
3p_ _ _3d _ _ _ _ _
N 1
N 2
N 3
ORBITALS- PLACE WHERE ELECTRONS MOST LIKELY
FOUND. Holds 2 electrons (pair) maximum.
SUBLEVELS- subdivision of a shell. s holds 2
electrons, (one orbitals)-found in all shells p
holds 6 electrons, (three orbitals)-second shell
and up d holds 10 electrons, (five
orbitals)-third shell and up
2
AFBAU PROCESS WHEN DIAGRAMMING AN ELECTRON
CONFIGURATION, ELECTRONS ARE PLACED FROM THE
INNERMOST(LOW ENERGY) TO THE OUTERMOST(HIGH
ENERGY) ORBITALS IN ORDER. ONLY THE OUTERMOST
ORBITAL AND SUBLEVEL MAY BE UNFILLED (EXCEPT FOR
SOME TRANSITION METALS).
HUNDS RULE WHEN FILLING A p, d, OR f SUBLEVEL
YOU MUST ADD ONE ELECTRON FIRST AND THEN GO BACK
AND PAIR THEM UNTIL ALL ELECTRONS ARE SHOWN. p
_ _ _
PAULI EXCLUSION PRINCIPLE ELECTRONS IN AN
ORBITAL MUST HAVE OPPOSITE SPIN NOTATION, ONE HAS
AN UP ARROW , ANT THE OTHER A DOWN ARROW,
3
FILLING ORDER 1s_ 2s_ 2p_ _ _ 3s_ 3p_ _ _ 3d _
_ _ _ _
Na 11 2-8-1
EX) Show the electron configuration of 1s_
2s_ 2p_ _ _ 3s_ 3p_ _ _ 3d _ _ _ _ _
2
8
1
THE PERIODIC TABLE INDICATES ONLY ONE ELECTRON
(ARROW) IN THE THIRD SHELL. THIS IS THE VALENCE,
AND YOU ARE NOW DONE!
After the first shell has 2 electrons, place 8
electrons in shell n2 as indicated on the
periodic table ground state
FIRST SHOW 2 ARROWS(ELECTRONS) IN THE FIRST SHELL